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HDR-FOX Hardware: Commissioning, Disassembly, Repair

Black Hole

May contain traces of nut
Commissioning Tests to Verify a Newly-Acquired HDR-FOX

The first thing you want to know, on receipt of an HDR-FOX from anywhere (particularly second-hand), is whether it works properly - even if you intend to install custom firmware, test the vanilla (unmodified) HDR-FOX first. These tests are also valid for checking the functional state of an existing HDR-FOX, although you might not want to be re-formatting the HDD!

On delivery, particularly when purchased from Humax Direct, you should unpack and check for external signs of damage immediately, preferably witnessed by the courier. They won't like it, they want to get to their next delivery, but it is a condition of their contract that when you accept delivery you are declaring safe arrival. It will be difficult for the seller to claim against the courier if transit damage was not noted at the time of delivery.

Check for any signs of damage to the outer packaging before opening, and then check the contents. Look for dents, scratches, cracks, misalignments. Look carefully for parts that do not seem to line up - I once had a HDR-FOX delivered where the metal case was distorted by having been dropped on one corner, and the obvious sign of this was that the plastic front panel didn't fit properly.

Note: delivery is the seller's responsibility, and the courier has a contractual relationship with the seller - not with you. You are entitled to a satisfactory working unit, and if it is not working for any reason you have a claim against the seller, not the courier. It is for the seller to claim against the courier, not you, but it will help the seller's case if you notify the courier of damage at the time of delivery. It is also not your responsibility to judge the suitability of packaging etc - so if the courier contacts you to request such information as a result of the seller making a claim, tell them you are not a packaging expert and you have no contractual responsibility to the courier (this has happened to me!).

Once you have accepted that it is intact physically, proceed to electrical checks:
  • Connect power, HDMI to TV, Ethernet to home network, TV aerial to aerial input, and aerial pass-through to TV aerial input. Note that the aerial leads should be decent screened types and kept away from HDMI leads (cross-talk with an active HDMI signal, especially at 1080p, can obliterate UHF TV reception).
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  • Regardless of which version of firmware you intend to use in the future, install the latest available Humax firmware (1.03.12 at the time of writing). Download and instructions available HERE (click), see "Official Firmware" and "Installing Firmware". Note: this is not pointless even if the firmware is up-to-date - it confirms that aspect of functionality.
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  • If in factory condition, HDR should start by showing the installation wizard. If it does not, go to Menu >> Settings >> Installation >> Factory Default - on a second-hand HDR-FOX I suggest accepting the option to format the HDD. Configure the HDR appropriately and allow it to tune (you can't do anything until you have at least one broadcast service registered). Ensure Menu >> Settings >> System >> Power Management >> Power Saving in Standby = Off.
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  • Check TV can still receive via its internal tuner (HDR pass-through), including with the HDR in standby.
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  • Cut a piece of thin paper 5cm x 6cm, and fold the end 1cm over to a right-angle (I find the inner pages of a weekend newspaper colour supplement ideal). Hang the paper over the fan exhaust (suspended by the folded strip) to block the exhaust opening. If the paper blows off at any point, you will know the fan has worked without having to watch it all the time (it is thermostatic). Note: on later models, the fan was fitted with the air flow inwards. The paper test may not work on these.
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  • Fire up the TV Portal (needs Ethernet) and check it loads. Start iPlayer and play something (anything). Exit the TV Portal. Note: iPlayer and YouTube do not work with pre-1.03.xx Humax firmware. Note also that iPlayer and YouTube can be temperamental at the best of times, even when everything is fully working.
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  • Tune to BBC2HD and set it recording. Tune to ITV1HD and set it recording. Tune to BBC1HD and wait 30 seconds, then press pause and skip back to the start of the timeshift buffer. The HDR is now recording three HiDef streams and playing back a fourth. Check for picture break-up, check the recordings for break-up. If break-up is seen, replay the recording to see if it was recorded like that or only on playback (won't be the same the next time if on playback). If recorded break-up is found, stop all recording and timeshift, and check the live transmission for signal problems.
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  • Schedule a recording to occur in the near future, and then place the unit in standby. After the recording has (or should have) taken place, bring the unit out of standby and check it.
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  • Ensure both tuners are working by recording BBC1HD and viewing BBC1 (non-HD). Check the BBC1HD recording was uninterrupted while viewing BBC1.
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  • If, after a couple of hours of multiple HD recording, playback, etc, the fan tell-tale is still in place, worry about the fan (mine dropped off in 20 mins, but it is rather warm today).
The above does not guarantee that absolutely everything is working as it should, but it does provide reasonable confidence. If it does not pass these, there are only a limited number of things you can do in an effort to get it going (without breaking any implied warranty): restore factory defaults, re-flash the firmware, re-format the HDD.

If there is no chance of a customer return, there is more that can be done to diagnose the problem with the aid of the custom firmware.

Steps for Resolving HDR-FOX Crash/Reboot Issues (click)

I originally posted these details on AVForums (here - click).
 
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OP
Black Hole

Black Hole

May contain traces of nut
Access to Internal Parts (Disassembly and Re-Assembly)

Handset


Instructions for disassembly and repair of the remote control handset are available here: https://wiki.hummy.tv/wiki/Remote_Disassembled. There are also useful details about a modification to improve the response of a worn cursor ring in this post (click).

The remainder of this article concerns the main unit.

Main Unit

Note: the details which follow are for the original version of the HDR-FOX. There was a hardware revision towards the end of production to accommodate a replacement tuner module (presumably the original module was no longer available and Humax preferred to re-engineer the HDR-FOX than stop production sooner than intended). The revised version can be identified by the UHF antenna input and output sockets being vertically in line instead of horizontally in line on the original build. Disassembly of the revised version is very similar, although not identical, to the process described below, and should pose no difficulty if the differences are noted as you proceed.

The HDR-FOX, unlike many consumer electronics products, is a pleasure to work on. Largely because of the metal case it is easy to get apart, requires a minimum selection of basic tools, and doesn't even have screws with security heads (weird slot arrangements designed to need special tools instead of standard screwdrivers, to keep dabblers out). In fact, the most difficult part of the operation is probably extracting it from your AV shelf in the first place!

More modern equipment tends to be packaged in plastic snap-together cases practically impossible to get apart without some kind of damage, or at least using security screws, because the requirements for putting equipment on the market are that the product is operated as designed and certified - not as may be "hacked" (physically or electronically). And of course to prevent litigation from people who get themselves zapped in the process, and modern packaging techniques are quicker (cheaper) to manufacture in the first place.

Reasons to need access to an HDR-FOX's innards:
  • Servicing (the only routine maintenance required is to clean out accumulated dust that prevents adequate cooling, the only serviceable part is the fan);
  • Replacement and/or upgrading of the hard disk drive (HDD);
  • Repair or replacement of a dead fan;
  • Removal of the front-panel display filter (make it bright green instead of dim orange);
  • Diagnosis and possible repair of faults.
Regarding the HDD, the HDR-FOX was available with 500GB and 1TB drives as standard. An HDR-FOX running the latest standard firmware can accommodate drives up to 2TB, and with the custom firmware the capacity is practically unlimited (using GPT formatting rather than MBR). Physically, the HDR-FOX HDD is a 3.5" SATA unit, up to 26.1mm thick (standard 1TB unit). See HERE (click) for recommendations on choosing an alternative HDD.​
Regarding the fan, see servicing or replacement details in post 3.
Regarding the display filter, if you find the front panel VFD (vacuum-fluorescent display) too dim or would prefer it to be green rather than orange, the orange filter can be removed by carefully peeling it away. The VFD gets dimmer with age, so even if it is not too dim now it may be in the future. If subsequently too bright, this can be moderated by installing the custom firmware 'redring' package and setting appropriately (WebIF >> Settings >> Settings for redring package). See also https://wiki.hummy.tv/wiki/Fixes_/_Work_Arounds_for_Known_Bugs#Display_Too_Dim.

If the HDR-FOX appears dead: don't forget to check the rear-panel mains switch is turned on, it's plugged in and turned on at the wall, the fuse in the mains plug hasn't blown, and there isn't a power cut - before deciding to "go in".

There are only five types of screw used in the assembly - three if you discount the screws used to hold the HDD and the fan into the drive caddy. The remainder are: three black screws that hold the cover on; one type of machine screw; and one type of self-tapping screw. All have the same size of head. The machine screws are used when the screw goes into metal, the self-tappers go into plastic.

Facilities and Tools Required
  • A firm and clear working area. Grovelling around on the floor in a tight corner is no way to work. If you are going to work on the best dining table, ensure all of it is covered (ie protected from being scratched) by a thick cloth, and make sure there is nothing trapped under the cloth that would scratch the table if the cloth moves (been there, done that, suffered the consequences). Then put something firm on the cloth (I use an A2 cutting mat for jobs like this).

  • A craft knife (only required to neatly cut the anti-tamper seal).

  • A medium-sized cross-point screwdriver (Phillips). Using the right type and size of screwdriver makes it much less likely the screwdriver will slip, or ruin the screw head. If the screwdriver is magnetic, so much the easier for manoeuvring a screw into a tight space.

  • A magnetic pick-up tool or pearl-catcher (if your screwdriver isn't magnetic).

  • A flat-bladed screwdriver (only required as a lever to remove the front panel assembly, if necessary).

  • White spirit and kitchen paper (only required for removing traces of the anti-tamper seal, or cleaning up glue residue after removing the display filter).
Anti-static facilities are not necessary for the disassembly to be described below. Any work for which such precautions would be necessary is beyond the scope of this article (and the abilities of the likely readership - if you know what you are doing sufficient to go beyond the limits of this guide, you will also know what to do already). As a general precaution when handling exposed electronics devices, keep the power off (and unplugged) when handling, use any exposed metalwork as a body contact to equalise static potentials, and avoid touching circuit boards except by their edges.

General Advice

As a general rule, and unless otherwise specified, re-assembly is the reverse process of disassembly (last part removed is the first part installed, etc). Photographs are provided in this article for reference, but in other cases (where there may not be any photographs or diagrams to follow) digital cameras are so easily available (practically anyone with a mobile phone has one) and cheap to run (no more paying for prints) that it would be foolish not to take numerous photos in the process of disassembly, so as to have a reminder of where everything fits later.

Mind your fingers on metal edges (especially inside the unit). It is very easy to pick up a "paper cut" by a casual brush against a sharp edge.

When inserting screws, you don't want them cross-threading or trying to cut a new thread in the hole instead of using the old thread (self-tapping screws into plastic). Give them the best possible chance by ensuring the screw is offered straight (not wonky), press it in and turn it backwards (anticlockwise) until you hear it "click". That means the thread on the screw has lined up with the thread in the hole, and now by turning the screwdriver clockwise the screw should drive into the hole using the existing thread.

With experience, it is generally possible to tell whether a screw is going in properly just by feel, and when it is fully home without over-tightening it. Being too forceful with a screwdriver risks stripping the thread or cracking the items (either the substrate or the object being fixed to it), requiring a difficult repair when it shouldn't have been necessary. When a screw is home, it's home - don't be tempted to do that extra nip up "just to be sure" (if there is a risk of a screw or a nut shaking loose, use some thread-lock on it - a special kind of glue). If a screw is being really stubborn, over-exertion with the screwdriver risks snapping the head off (with no end of a headache trying to get the rest of it out of the hole).

It is vital that screws and other small parts are stored safely once removed, preferably in such a way that they are easy to identify for re-assembly. Garage workshops use a magnetic tray to store screws etc, and they won't spill out if the tray is tipped. A kitchen baking tray for jam tarts is handy as it has a dozen compartments. Label the compartments if appropriate. Alternatively, a piece of thick card can be written on with labels and screws secured to it under sticky tape. Storing screws for the HDR-FOX is not such a problem, because of the limited number of types and easy identification. A simple storage box of some kind will be adequate.

Security Seal

An anti-tamper security seal is fitted to provide evidence of internal access to the HDR-FOX, bridging the case cover and the base. The cover cannot be removed without damaging the seal, and any attempt to remove it (even with a hot air gun) is doomed to failure (the glue takes a portion of the silver backing with it, revealing a "void" logo).

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The seal is no longer relevant, because any warranty remaining on HDR-FOX units has run out. Cut through it with a knife blade at the seam of the case parts, or peel it off and remove the residue with some white spirit on a wad of kitchen paper (nail varnish remover might also work).

Disassembly

1. Case Cover


The case cover is held in place by three screws on the rear panel and by lapping into the front panel assembly. Removal of the cover is by removing the three screws, then sliding the cover back by half an inch or so to release it from the front panel, then lifting off. It may be necessary to ease the cover away at the sides to gain clearance from the base.

The three screws in question are black in colour, and identified in the photo below by pink arrows.

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Access with the case cover removed is sufficient to give the unit a general dust out. Use a soft paint brush and a vacuum cleaner.

2. Disk Drive and Fan Caddy Assembly

Removal of the disk drive and fan caddy assembly is necessary to replace the HDD or service/replace the fan (see also post 3). The caddy is the large black item near the centre in the photo below.

Disconnect the HDD power and data cables from the main circuit board, as shown by the pink arrows below. The data cable (flat red) just pulls off; the power cable has a lever latch which has to be squeezed at the top to release. Note how these cables pass under other cables.

The fan power cable (blue arrow) also has to be disconnected in order to remove the caddy assembly. However, it is hard to reach the latch while the caddy is still fitted.

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The caddy assembly is fixed in place by four machine screws, two shown below (pink arrows) and two more on the other side of the caddy. With the screws removed, the caddy assembly can be carefully lifted out (while not straining the fan cable) to gain access to the fan connector, and squeeze the latch to disconnect the cable.

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The caddy assembly complete (underside, showing the HDD):

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Caddy assembly compete, view from rear as fitted in HDR-FOX (fan side):

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To remove the HDD from the caddy: disconnect the combined data and power cable from the HDD (accessed through an aperture in the caddy). Remove four large-headed screws (two on each side of the caddy, visible in the photo third above - these screws pass through anti-vibration mounts (blue). The HDD can now be removed from the caddy, but is a tight fit between the anti-vibration mounts.

To remove the fan from the caddy: remove four large self-tapping screws (as shown in the photo above). Note the position in which the fan cable exits the fan, and the label side of the fan is visible from the rear of the caddy.

These are the individual parts that comprise the disk drive and fan caddy assembly, including the screws which secure the assembly into the HDR-FOX chassis:

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3. Front Panel Assembly

Removal and dismantling of the front panel assembly is required to access the VFD orange filter. The circuit board in the front panel assembly receives infrared data from the remote control handset, operates the touch-sensitive front panel controls, and includes the wake-up timer for scheduled operations from standby, so it is essential for the normal functioning of the HDR-FOX (the unit won't even power up without it).

To prepare for removal: disconnect the cables from the main circuit board (pink arrows below - both connectors have lever latches); remove the machine screw securing the earth strap (green arrow); remove three machine screws securing the front panel moulding to the main chassis (blue arrows). Note that the centre screw is missing on the unit illustrated, and possibly has not been fitted on any units.

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To remove the front panel assembly, three plastic tabs must be carefully released from their latches on the chassis along the top, three similar tabs along the bottom, and one metal tab on each end. A flat-bladed screwdriver will be needed for the bottom latches. The technique is to start at one end and work along: release the top and bottom latches and a side latch, and ease that end of the assembly away from the chassis so that the latches don't click back. Then release the middle latches top and bottom and ease the end away further. And finally the latches at the other end to release the whole assembly away from the chassis.

Alternatively, if that proves tricky, some pieces of thin card or stiff plastic about 1" square can be inserted under each latch one at a time, and the card prevents the latch locking (without over-straining it) so that one does not need to be an octopus. With card under each latch along the top and bottom, the side latches will be easy to release.

Detail of a top latch at the right hand end - the other latches are similar:

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Front panel assembly complete (note the metal-covered sponge pad that provides an earth contact to the main chassis):

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To disassemble the front panel assembly: Remove two self-tapping screws that secure the USB interface board and earth strap (left hand end in the photo above); remove the USB interface board itself; remove five self-tapping screws that secure the front panel circuit board; carefully release plastic latches, lifting the circuit board from either end until it releases all the way along.

These are the individual parts that comprise the front panel assembly:

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The VFD orange filter is attached to the VFD by adhesive; carefully peel the filter off if you want to remove it, and clean off any residue from the VFD glass with a mild solvent such as white spirit or nail varnish remover on a wad of kitchen paper. Avoid soft plastic parts.

4. Power Supply Unit (PSU)

Extreme caution should be exercised when dealing with the PSU. Apart from (obviously) disconnecting the unit from the mains before opening the case (and only plugging it in again, preferably via a mains isolating transformer, once the necessary conditions have been established for any live testing that is required), the PSU may (according to design) hold a dangerous charge even with the mains disconnected. An absolute minimum of handling is advised in the case of all such PSUs.

Note that the HDR-FOX chassis is not earthed, relying instead on double-insulation for standards compliance (and also avoiding mains hum loops in analogue audio connections*). Compliance requires that one fault is not injurious - so earthing is a backup for a single layer of insulation (if the insulation fails, current flows to earth and the fuse blows), or double-insulation provides a second barrier if the first fails. The problem with double insulation rather than earthing is that if the first insulating layer fails (wears through), the second layer means you don't know about it until the second layer fails as well (with undesirable consequences).

* I recently acquired a spare PSU for my notebook computer, so that I can travel with the PC without having to extract the mains supply from its normal place on my desk. The PSU brick is a cheap Chinese replacement bought on eBay, and works fine... until the PC is hooked up to an audio system, when a nasty buzz comes through that never happened with the OEM PSU. I had a pretty good idea what was causing it, and when I measured the OEM PSU there is no DC path through the PSU from the mains earth to the 0V DC pin, but the replacement PSU does. I broke open the brick (not as easy as YouTube videos would have you believe), found the circuit board track that (unnecessarily) connects the mains side to the DC side, and removed it - problem gone. NOT RECOMMENDED UNLESS YOU REALLY KNOW WHAT YOU ARE DOING. There are a good few stories I can tell about close calls with mains circuits...

HDR-FOX PSU removal may be required if the PSU has failed. The PSU does not include any serviceable parts, such as fuses.

The photo below shows the disassembled HDR-FOX with just the main circuit board (green circuit board, right) and PSU (yellow circuit board, left) remaining. Access to the PSU requires removal of the disk drive and fan caddy, but not the front panel assembly.

Remove the mains cable assembly by lifting the cable gland and mains switch out of their rear panel slots (pink arrows), and disconnect from the circuit board by releasing the lever latch on the connector (blue arrow). Disconnect the DC cable at the main circuit board connector by releasing the lever latch (second blue arrow). Remove two machine screws (green arrows).

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5. Main Circuit Board

The main circuit board will not normally need to be removed from the chassis, unless one desires to clean under it. If the main circuit board has failed, the entire HDR-FOX has failed and the PSU, front panel, and disk drive & fan assembly, become available as spare parts for other units, and the chassis is scrap with the main circuit board. However, the chassis itself may be useful - who will be the first to squeeze a home theatre PC (HTPC) into an old HDR-FOX case?

One of the disk drive caddy mounting screws also holds the main circuit board. With that already removed:

On the rear panel: remove the rubber slot cover from the Common Interface slot on the rear panel; remove one machine screw from above the HDMI socket; remove three self-tapping screws from the SCART/AV socket assembly, the SPDIF port, and the Common Interface module.

Remove two machine screws holding the main circuit board to the base of the chassis. The main circuit board is now free to remove from the chassis.

These are the individual parts that comprise the PSU and main circuit board assemblies:

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Repair

Hard Disk Drive (HDD)

HDD file system errors can be recovered by software - see Quick Guide to Disk Recovery (click). If, on the other hand, the HDD fails mechanically or its SMART diagnostics report accumulating errors (WebIF >> Diagnostics >> Disk Diagnostics), replacement is the best option (and the opportunity can be taken to increase the storage capacity, effectively unlimited by use of the custom firmware and GPT disk formatting). See https://wiki.hummy.tv/wiki/2TB_Disk_Installation_Blog.

Fan

Servicing or replacement of the fan is discussed in detail in post 3.

Front Panel Assembly

The front panel sub-system is essential for powering up the HDR-FOX. Repair of a failed front panel assembly will normally be by replacement of the complete assembly or the circuit board within, using another (failed, but with a working front panel) HDR-FOX as a donor.

Front panels have also been available as spare parts direct from Humax, and the assembly is common with some other Humax models.
The front panel board in the DTR-T1000 can be used in the HDR-FOX.
PSU

If a replacement working PSU is not available as a spare part from Humax or from a donor (failed) HDR-FOX*, it may be possible to repair the existing PSU.

Typically, PSUs fail (or degrade) due to their electrolytic capacitors (the black cylinders with white stripes and markings in the photo above - the PSU is the yellow circuit board on the left) going "dry" (ie aged beyond their useful life). A dry capacitor can sometimes be seen to be bulging slightly. In these cases, the PSU might be brought back to life by replacing these capacitors, and sometimes kits of spare parts for specific PSUs are available on the Internet. Some skill with a soldering iron will be required, but it is not a difficult job to do if you have the tools.

In the event that a replacement PSU is unobtainable, it is not outside the bounds of possibility to adapt another PSU for the purpose. This will require some analysis of a working HDR-FOX to establish the voltage, current, and switching requirements, and I will consider doing so when there is a specific need.

* It appears the PSU from a Foxsat-HDR may also be suitable:
Agreed. Looking at videos/photos of the Foxsat-HDR internals, the chassis layout seems identical to the HDR-FOX and the PSU matches visually. There is every reason to believe it is the same assembly.

Re-Assembly

I hate to say it, but re-assembly really is the reverse process of disassembly - use the photos above for reference. In order:
  1. Main circuit board into chassis;
  2. PSU into chassis and reconnect to main circuit board;
  3. Assemble front panel assembly and fit to chassis; reconnect to main circuit board;
  4. Assemble disk drive and fan caddy assembly; fit to chassis; reconnect to main circuit board;
  5. Case cover.
Latched connectors must be pressed home until the latch clicks. This should not require a great deal of pressure, but the more contacts there are on the connector the more force it will need.

The most often neglected thing is to account for all the screws, and their correct places for the different types of screw:

Main circuit board - 3 machine screws (one on rear panel, two inside); 3 self-tapping screws (rear panel).​
PSU - 2 machine screws.​
Front panel assembly - 5 self-tapping screws (front panel circuit board); 2 self-tapping screws (USB connector circuit board); 4 or 3 machine screws (one on the earth lead to chassis, three or two holding the front panel assembly to the chassis).​
Disk drive and fan caddy - 4 large self-tapping screws to secure the fan; 4 large machine screws to secure the HDD; 4 machine screws to fit the caddy to the chassis.​
Case cover - 3 machine screws, black.​

For details of where the screws are fitted, see the relevant section in the disassembly instructions.

Connectors

This is a checklist to ensure all the internal connections have been re-connected:
  • Mains cable assembly to PSU circuit board
  • PSU circuit board to main circuit board
  • Front panel assembly earth strap to chassis
  • Front panel USB connector circuit board to main circuit board
  • Front panel circuit board to main circuit board
  • Fan to main circuit board
  • HDD to main circuit board (power and data)
 
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OP
Black Hole

Black Hole

May contain traces of nut
HDR-FOX Fan Issues

In the event that an HDR-FOX becomes unreliable, particularly after an extended "on" period, one might suspect it is suffering from overheating. Users of the custom firmware (CF) are able to monitor internal temperatures using the sysmon package, or check current and historical high temperature records in the HDD SMART data via WebIF >> Diagnostics >> Disk Diagnostics (sysmon also uses this data as the only means available to access temperature sensing).

Note that satisfactory temperature readings do not imply there is no possibility of overheating - any layer of dust on critical system components (eg the processor) insulates them from the cooling air flow, and only the temperature of the HDD is actually monitored. Therefore, when the case is open for any reason, take the opportunity to remove any dust build-up from inside the case. A vacuum cleaner is good for this. However, if the HDD reports excessive temperatures, and assuming the unit is not being operated in a high-temperature environment, the likelihood is that there is something wrong with the air flow, and therefore the fan.

Assuming the fan (while installed in the HDR-FOX) isn't working, the problem could be the fan itself, or the drive from the main circuit board. The drive is thermostatic, so just because the fan is not spinning at any particular moment, or there is no voltage supplied to it, does not automatically lead to the conclusion there is something wrong. The commissioning tests in post 1 provide a means to check, but take time to achieve a result (and even then a negative result is not absolutely definite - it might be simply too cold to need the fan running).

CF users can install the fan package and set it to 100%. This should ensure the fan is forced to run, but again a negative result cannot absolutely rule out a software problem - this is the life of a test engineer: results build up a picture and a history, and add to a probable conclusion but rarely a definitive one. (The fan package sets a minimum continuous operating speed for the fan, so that it never turns off completely but still speeds up if the thermostat demands. This is intended to reduce the temperature extremes within the case, at the expense of a very slight increase in noise. Setting a minimum speed of, say, 40% should still be barely audible but very much reduce the occurrences of the fan ramping up to full speed under thermostatic control.)

If one suspects the fan isn't running when it should be (eg the HDD is reporting excessive temperatures, or the tell-tale remains in place over an extended period), then check the actual fan unit as follows below (see Servicing and Testing an HDR-FOX Fan). Once the fan unit is proven working, this is your tester for the driver output from the main circuit board. (Measuring the output directly requires running the HDR-FOX from mains with the lid off and disassembled, and is in any case problematic so is not a suitable procedure for the inexperienced - and those with relevant experience will already know what hoops to jump through.)

Working Fan, Dead Driver

With the fan proven, but still no response when installed in the HDR-FOX, there is no choice but to make alternative arrangements for system cooling. It is immaterial why the circuit board is not providing a fan drive - it just isn't, and the function needs to be reinstated another way. You could (in order of convenience, but reverse order of preference):
  • Place a fan external to the case so that it forces air through the perforations in the case;
  • Bypass the fan controller by linking the fan's black wire to a 0V point and the red wire to a source of 12V (eg the HDD supply - the fan will be quite noisy but at least there will be an adequate air flow);
  • Fit a fan with its own thermostatic regulation and a temperature sensor somewhere - eg taped to the HDD case.
(This section to be developed further with recommendations for parts and fitting)

Dead Fan, Working Driver

If, on the other hand, the fan is shown to be unserviceable, the best option is to replace it with an equivalent unit. As the fan is supplied in bulk to Humax, it is likely to be difficult to obtain the identical part as a retail item, but search for the model number ("fan AUB0512LB") on eBay and you may well find the part offered as a second-hand item recovered from scrap units. When such a unit is received, test it as described below and reject if it does not pass the battery test.

Failing that, look for a compatible (rather than identical) new part. The key specifications are:
  • 50mm x 50mm (thickness is unimportant - the original unit is 15mm thick but the housing will accommodate up to about 25mm thick);
  • Mounting holes on 40mm x 40mm pitch (normal for a 50mm fan);
  • 12V DC brushless.
See below for an illustration of the original fan. The "0512" in the model number indicates the physical size (5cm square) and operating voltage (12V).

The connector is polarised and latched, 3-pin 2mm pitch, with the red wire for positive supply, black wire for negative supply, and white wire for controller feedback (not used on HDR-FOX). This, however, is relatively unimportant. Fans supplied as spares for PCs and such like are easily available, but have (commonly) a 2.5mm pitch connector which clearly won't fit the connector on the HDR-FOX circuit board. Even if the connector appears to be exactly the right one, check the wires are in the right places (compare with the original unit), and don't try to force it to fit because there may be slight differences not obvious to the eye. If it's going to fit, it will fit easily.

The answer is not to worry too much about the connector, and simply splice the connector from the dead Humax fan onto the cable for the new fan. This can be done temporarily (or even permanently, if you are not into soldering) by stripping some insulation off the wire to the old connector and inserting it into the connector for the new fan (and then taping it over to secure it). In any case it would be wise to test the new fan with this arrangement before making permanent modifications, in case you need to send it back. Soldering the old connector onto the new fan, by cutting and joining the cables and insulating the joints, is preferred in the long term. Ensure the resulting cable is long enough to reach the circuit board connector without strain (this also provides an opportunity to lengthen the cable for ease of access), and the best way to insulate the joints is to use a narrow diameter heat-shrink tubing* (but insulating tape will do). For this application the white wire is immaterial, and if the new fan has only two wires (hopefully red and black) the white wire from the old connector can be ignored.

* Heat-shrink tubing is readily available in small quantities and multiple sizes/colours from eBay, the best types have a hot-melt glue inside the tube to seal against water ingress. Clear tube may not be pretty, but it allows for inspection of the joint. The best way to shrink the tubing is to use a hot air gun - a paint stripper will do if used carefully; a craft "embossing" gun is less fierce and preferred. Hair dryers are not hot enough. Dabbing the tube with a soldering iron does not result in an even shrink, and makes a mess of the iron (but if all you have is a hammer, everything looks like a nail)!

When assembling a new fan into the HDR-FOX HDD caddy housing it, ensure the air flow direction will be correct. The original fan has the label towards the outside, and exhausts air in that direction. A new fan should have arrows moulded into the edge of the frame indicating the direction of rotation and the direction of air flow - make sure the fan is fitted so that the axial arrow points outwards.

The original fan is secured with quite large self-tapping screws into the (approx) 4mm holes in the fan itself. If the original screws are too large for the new fan, use smaller screws (don't risk splitting the fan frame by forcing in the original screws, and the risk of splitting can be minimised by inserting the screws in stages: half a turn forward, quarter of a turn back, and repeat until home). Even better, use machine screws (bolts) with nuts on the rear, an appropriate size to pass through the holes in the fan freely. If the heads on the screws are too small, so that they pass through the holes in the caddy, use washers to make them (effectively) larger. The screws should be flat-head or pan-head, not countersunk. M4 x 20mm pan-head (plus nuts) would be correct for the original fan, and (I suspect) most other fans too (if the fan is thicker than 15mm use 25mm or 30mm screws).


Servicing and Testing an HDR-FOX Fan

The fan unit is accessed by removing the HDD caddy (see post 2) and then removing the four cross-head screws that secure the fan to the caddy.

IMG_2172-512x274.jpg

Fan units are, in themselves, extremely robust, and are very unlikely to fail within the service life of the host equipment. What they might do, though, is seize up due to dirt/dust clogging up the bearing. The fan rotor should spin freely for a couple of revolutions if flicked with a finger, before coming to a stop due to the magnetic braking. If the motion is obviously stiff and restricted, chances are that life can be restored simply by cleaning and lubricating.

Dismantling

It is not obvious, but there is nothing but magnetism holding the rotor into the overall frame of the fan unit. The problem is to remove the rotor without damaging it (ie the fan blades), as is likely if any hard tools are used in the process.

Take about 18" of thin string and tie it into a loop. Using a small screwdriver if necessary, hook the string under one fan blade on one side of the rotor, and two blades on the other side (the rotor has an odd number of blades, so doing it this way will keep the forces central).

IMG_2173-512x527.JPG

Now pick up both parts of the loop, hold the fan frame down with the other hand, and pull (probably quite hard). The rotor will separate from the frame (with something of a 'pop' - try not to let it fly into your face, safety goggles are advised for the timid and/or litigious).

[It is also possible to separate the rotor from the frame by pressing through the frame from the label side - but it requires nerve, and do not use tools.]

IMG_2162-512x282.JPG

Servicing

To service: clean everything, particularly inside the cavity of the rotor (especially the pin) and inside the centre hole in the stator unit (in the centre of the frame). Use a cotton bud, and if necessary only a very mild solvent such as white spirit. To get inside the hole in the stator try twisting some kitchen paper into a stiff thread.

Now put the tiniest blob of grease on the tip of the rotor pin (I find Vaseline handy for this kind of thing - it's not the best grease to use in most circumstances, but it is better than nothing and it is easily available in small quantities). Being runny, oil is not suitable.

Finally reassemble by fitting the rotor back into the stator, taking care to line the pin up with the hole so that the grease on the pin goes into the hole rather than anywhere else. The reassembly requires pressure to overcome the magnetic resistance again.

Even if it did not do so before, the rotor should now spin freely.

Testing

To test the fan: use thin solid-core wire to jury-rig a supply to the red and black terminals. I had a hunt around to see what household items could be used for this, and found that paper clip wire is too thick to be inserted into the fan connector. Telephone wire would work, but not everybody has some of that (without ripping it off the wall). I hit on a couple of cable ties (the type with a metal wire core encased in a plastic or paper strip, used for tidying cables or closing plastic bags), stripped a quarter inch of the plastic off each end, and they work as connecting wires.

For a power supply, I came up with a 9V PP3 battery borrowed from a smoke alarm (5V from a USB wall wart charger isn't enough to get the fan spinning, and personally I have a laboratory power supply to use). Be careful to observe the correct polarity. I've used a rubber band to hold the wires onto the battery contacts for this photo, but for a quick test it is easier to simply grip them in place for the amount of time it takes to see the fan spin up (battery terminal marked "+" to the red fan wire, "-" to the black fan wire):

IMG_2174-512x337.JPG

NB: don't try this with just any fan - this is a 12V fan so a 9V battery isn't going to kill it, as long as you get the terminals the right way around. Make sure you know what you are dealing with before hooking up any source of power to anything!

If at first the fan doesn't work from the battery, check the battery isn't dead!* If the fan is still a bit stiff, 9V might not be enough to get it spinning but the full 12V could - but if the fan is that stiff even after servicing, it's near the end of life anyway.

* In the absence of any more sensible ways to test the battery, such as pressing the "test" button on the smoke alarm, you could try putting your tongue across the battery terminals - you'll soon find out whether the battery has any life in it, even if you no longer do. If in doubt, get your favourite sibling to test it for you. :rolling:

Reassembly of the fan into the HDR-FOX is the reverse of disassembly; use the photos in post 2 as a guide.
 
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af123

Administrator
Staff member
I just swapped the hard drive from a T1000 to a foxsat (same caddy in each so just swapped them). Here are the fans which were in those.
Foxsat on the right, T1000 on the left.

 
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Wallace

Traveler 34122
Excellent article BH.

I remember having to replace a fan on one of my HDRs not too long after purchase. As I had already opened the box to remove the orange filter and invalidated the warranty, I couldn't be bothered sending it back for such a 'trivial' job as fan replacement.
 
OP
Black Hole

Black Hole

May contain traces of nut
Suggestion: we should set up some kind of pool (physical or virtual) for dead units to use as spares, rather than just have people mention it on the forum and then get forgotten, only to find some time later that when somebody needs it they've had a clear out and got rid.

How could we do this? I don't mind setting up a parts store if there is a demand. Maybe people donate to the store and then get some kind of payment if/when parts are sent out? It could even become a repair facility for people not happy with opening up the case themselves.

I don't want to be unnecessarily pessimistic, but I expect failure rates to increase before too long...
 
OP
Black Hole

Black Hole

May contain traces of nut
After consideration, I don't think "virtual" works. Parts need testing to verify as working, and to make that a relatively easy job that means having a dedicated HDR stripped down for bench work.

I guess there are a few of us that could do this, if there was a demand.
 
OP
Black Hole

Black Hole

May contain traces of nut
I had recourse to that guide recently, when changing my HDD.
Its very good - the only caveat is that for a certain class of colour blindness (which I have) the comments about pink and blue arrows don't help, but it's easy to work around.
dandnsmith : How do you propose I improve the annotation, given that I wanted to identify parts on an essentially green background?
 

dandnsmith

Forum Supporter
Having looked at it again, carefully, I think you did an excellent job - for me a more intense red colouration on the pink arrows would make them stand out better (but thats just for me). I've been coping with this problem for many decades - even to working with electronic parts identified by colour bars (eg resistors) - and invoke help if there is any suggestion of confusion (my wife assists on request)
 

everthewatcher

Forum Supporter
The original fan has the label towards the outside, and exhausts air in that directio
That's interesting - the HDR V2 here is mounted to blow air inwards. I've cut a hole in the side of the HDD carrier to take advantage of this to give a little airflow over the heatsink on the main chip.
 

everthewatcher

Forum Supporter
If you have the HD carrier out I recommend looking at the state of the four blue HD mounting grommets.

On two of the three units I've had apart so far they were suffering from PVC plasticiser migration due to the styrene component in the ABS HD carrier. This makes them less compliant as well as oily, and the ABS carrier gets damaged too - this is why you don't let PVC cables contact expanded polystyrene (EPS).

I've swapped them for some thick 10mm grommets I had to hand. They're still PVC but they'll do until I find something better.
 
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OP
Black Hole

Black Hole

May contain traces of nut
I didn't notice any problems with the one I had apart - is this easily spotted? The one I stripped is my cold spare, so it may be late production (but nonetheless pre-RE), and hasn't been above room temperature.

What is the consequence?

I have never heard of this PVC/EPS issue before.
 

everthewatcher

Forum Supporter
I didn't notice any problems with the one I had apart - is this easily spotted? The one I stripped is my cold spare, so it may be late production (but nonetheless pre-RE), and hasn't been above room temperature.

What is the consequence? I have never heard of this PVC/EPS issue before.
It's easily spotted - the grommets have a sticky/oily film and the HD carrier where they touch looks as if it's been slightly melted. The one here that isn't affected is a V2 ('RE') one.

It's a very well-known problem with PVC and PS/EPS. It's why PVC cables are always packed in polyethylene bags when EPS packaging is used for electrical kit and, as the PVC can eventually become brittle as the plasticiser migrates out, it presents a serious hazard when fixed mains cabling comes into contact with EPS insulation in buildings and even boats and RV-type vehicles.
 
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