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Poor signal needs troubleshooting 101

Discussion in 'HDR-1800T/HDR-2000T Freeview Recorders' started by monusalv, Feb 15, 2015.

  1. monusalv

    monusalv New Member

    So we finally gave up on the 9200 - didn't see the point in sourcing another disk after 2 had already corrupted - and now proud owners of 2000T. First impressions are ok but if you're taking the display off to save costs, the dim/bright red for standby/recording is pretty poor.

    Now to the major concern - I'm getting persistent drop-out of the sound for a couple of seconds, mainly on HD channels, and it's really annoying. Also, I regularly have recordings marked as failed because of poor signal, although they're ususally fine, just the same sound drop-outs and sometimes a pixelated couple of seconds. Interestingly, if I rewind a sound drop-out and then re-play it, I frequently get the full sound on second time through. Very occasionally I'll get blank screen but only for a second and usually too quick for the hummy to put up a "no signal" notice.

    I've searched through the forums and tried to get a step-by-step list of troubleshooting steps to take in the best sequence but it all seems a bit random. There seem to be plenty of posts with my signal strength but no problems, so not sure where to start. Do I need to check for interference and if so how? I can't see significant drops in signal, maybe they're too quick for the hummy so show, so should I just move the aerial outside; buy a booster? For info, I'd really like to split the signal to provide aerial sockets around the house.
    Current stats:
    Signal is upper 60's strength with 100% quality and fairly steady, aerial is new Labgear 454W/S, bought when on offer at crudefix, mounted in loft (this boosted signal up from low 60's with old aerial). Down wire is bog standard coax, probably 1970's (possibly mid 80's) ?.
    Location is near Reading (RG10 8nn) postcode so our recommended transmitter is Crystal Palace but on the edge of the range. Depending on your line-of-sight with local buildings, hills etc the alternative is Hannington.
    TV is 1yr-old Samsung LCD and never had the same problem.
    I have radio ham within 1/2 mile if that's relevant but can't see any other pattern which might indicate interference problem.
    Last edited: Feb 15, 2015
  2. MartinLiddle

    MartinLiddle Super Moderator Staff Member

    I think everybody agrees about that.

    I really don't think a booster will help.
    Is the postcode correct because the Royal Mail website doesn't recognise it?
    Is your aerial pointing at Crystal Palace?
  3. prpr

    prpr Well-Known Member

    This is almost certainly NOT a hardware fault and almost certainly IS a software fault. It corrupts its filesystem on a regular basis (others will deny it but mine did it regularly). The cure is to format the disk (which recreates the filesystem and trashes all your recordings).
    Oh. If it pleases you. It wouldn't please a lot of us.
    I would get rid of that and replace with CT100/WF100 or similar. Don't use cheap cable and don't use plastic plugs. Use decent quality screened (metal) fittings.
    Duh (where's that dunce's emoticon?). It's fairly obvious that "nn" is a placeholder for his real postcode which he sensibly chooses not to reveal.
  4. Black Hole

    Black Hole May contain traces of nut

    I presume your TV shows none of these problems when playing from its own tuner - is the TV aerial daisy-chained through the 2000T?

    On the Humax, while watching a problematic HiDef service (or any problematic service, come to that), on the handset press "OK" then "i" (info)*. An information panel should appear with technical details, in particular you want the channel number "Ch##". Now go to Menu >> Settings >> System >> Signal Detection* and select the channel previously noted (it will probably already be loaded). Spend a few minutes monitoring the signal strength and quality bars. If the quality figure remains rock solid at 100% and the strength is steady and at least 40%, you can rule out any problem with your aerial installation and distribution.

    If the signal strength figure is lower than 40% and the quality figure takes dips below 100%, you have a poor signal (the 40% strength figure is fairly arbitrary - the point is it is on the low side and affecting reception quality, you can still have 100% quality at 30% strength). You may find it improves significantly if you attend to the quality of the cables and connectors between the wall point and the aerial input. Don't use the nasty thin cable and plastic plugs that supermarkets and DIYs sell. Keep any HDMI cables away from the aerial leads (do not underestimate their ability to interfere with UHF TV, particularly when viewing at 1080 resolution).

    If, on the other hand, the quality figure takes dips below 100% and the signal strength is 100%, the incoming signal is too strong and needs attenuating. If the strength is in excess of 40% and yet the quality is dipping below 100% on occasions, you need to investigate possible sources of interference.

    When you have ruled out reception conditions as the source of your problem, we now focus on the Humax itself. Disk format errors can result in similar effects. First, make certain these are not being caused by HDMI interference: make a series of recordings with the HDMI lead removed (disconnected at the Humax end). Obviously the HDMI lead must be restored to play back the recordings (or use SCART/phono), and if the glitches remain the HDMI lead is ruled out.

    We now presume that the glitches remain, despite any of the interventions above. Perform a Restore Factory Defaults operation: Menu >> Settings >> Installation >> Factory Default*, and accept the option to format the HDD (this will wipe your existing recordings, and require retuning and resetting your recording schedule etc).

    If this still does not fix it, the unit is faulty and should be returned to the retailer for replacement.

    * These instructions are for HDR-FOX on the presumption that they also apply to 1800T/2000T.
    Last edited: Feb 15, 2015
    cdmackay and af123 like this.
  5. prpr

    prpr Well-Known Member

    I thought I already said that... I meant the cable the whole way from the aerial to the receiver.
  6. Black Hole

    Black Hole May contain traces of nut

    Yes, you did, but I was writing a 101. I covered the things the average user can reasonably deal with (which stops short of the downlink from the antenna to the wall plate), and if there is a problem upstream of the wall plate my approach will diagnose that there is and the user can get it looked at.
  7. monusalv

    monusalv New Member

    Thanks all for your replies.

    prpr is correct about being cagey with full postcode, .
    Yes, aerial is pointed correctly by compass per UKFree.tv bearing.
    Yes, TV is daisy chained through Hummy and except for very occasional glitches (less than a couple of times a month) I get no signal errors on the TV. I've put those down to transient interference from, say, aircraft as Heathrow is directly on line of sight to transmitter mast.

    BlackHole: thanks for 101 posting on signal strength/quality etc - just what I was hoping for.
    Whenever I've checked signal quality on all channels (mux not virtual) is 100% constant. This evening on standard power channels my signal strength is 76-78%+ and on C33 it's 72%. Usually I get at least 65%+ and C33: 60%+ and pretty constant (say wavering +- 1% but nothing wider than that). So I'm going to assume it's not under/over signal strength.
    That suggests I must go down the interference route, but as there's a family's worth of recordings it may take a while to clear them off before I could re-format. I'll try swapping round HDMI leads to see if it makes any difference. It's one of those frustrating ones as I can go one evening with everything fine, then the next it's crap. I may try and keep a better record of channel, times, anything else I can think of, to spot if there are any patterns.

    A couple of other points I hadn't mentioned before
    1) This is a HumaxDirect reconditioned box (hey - just found they've closed the site down??)
    2) Is there a known issue with sub-titles being completely out-of-sync. On my recordings, the subtitles play 15-20 secs ahead of the screen dialogue.

    Busy week but I'll try to check back with any updates.

    BTW I'd reformatted the 9200 a couple of times but it still started duplicating entries after a few weeks and the replacement disks I sourced wouldn't boot up from standby so it just made sense up upgrade to HD PVR. Without opening a digressive can of worms, if not 2000T, then what should I have bought? No clear consensus on here so I went with the best bang-for-buck-up-to-date model I could find as it's not something I change very often and I wanted longest support life.
    Last edited: Feb 16, 2015
  8. Black Hole

    Black Hole May contain traces of nut

    Your "virtual channel" is a "service".

    Copy them off to USB. The HiDef recordings won't decrypt, but they will still play (on the original recorder only).

    This will build up hearsay, not provide definite proof. Do what I said and switch to an analogue connection for a while - only for as long as it takes to observe a glitch in that configuration, and then you have eliminated HDMI as a factor.

    These statements are contradictory. Your recon unit has a 1 year warranty, buying a new one would have got you a 2 year warranty. If buying recon, you could have gone for a HDR-FOX T2 - we are the support service for that!
  9. prpr

    prpr Well-Known Member

    I don't understand the relevance of "re-formatting" to a source of interference. What do you hope to achieve by this?
    Yes, it does that, sometimes even after that short a time. This does not mean the disk itself is defective and changing it won't help. It is just crap software. You can't fix it. "Put up with it" or "buy something else" are your only options.
    A recon. HDR T2. Much better machine (in our opinions).
  10. MontysEvilTwin

    MontysEvilTwin Well-Known Member

    I bought a graded HD-FOX from Humax Direct and it was terrible. It worked fine for about 15 minutes than the tuner stopped working and could only be made to work again by switching off at the mains. Then the cycle repeated. They replaced the unit and the new one was fine. Is this relevant? I'm not sure, but I have read a number of reports of people buying graded units and having problems pretty much straight away. I have always wondered if their approach was to fix egregious faults, then do a factory reset and minimal testing. Any less obvious/ intermittent faults would then effectively be tested for by the end consumer.
    Once you have done your troubleshooting, if it still is not right, I'd contact them for a refund. As the site is currently defunct, I doubt they will supply a replacement.
  11. Black Hole

    Black Hole May contain traces of nut

    It's the way of the world. Testing by the end user (and remedy by refund or replacement) is cheaper than production line testing. What have they got to lose? Reputation, and that seems a minor consideration these days.
  12. monusalv

    monusalv New Member

    Latest tests suggest that
    a) the sound drop-outs are not exclusive to HD channels, I was getting them on SD BBC1 today,
    b) Unplugging the HDMI cable and using AV leads or Scart leads appears to resolve the problem (although I'm no longer getting HD quality tv).

    So, is the suggestion that the HDMI is generating interference, or that it's periodically picking up interference from elsewhere? Given that all my coax leads are fairly old stock from analogue days, do I start by replacing the old coax with something like WF100 and F-type connectors (as per SatCure recommendations) or get a new HDMI cable - and if so how to I know what's a quality HDMI cable other than by price?

    Just adding a bucketful of thanks for your continuing help here.


    @prpr: relevance of re-formatting is that if the HDMI test was fine, I may need to:
    and yes, I keep forgetting it's easy to move recordings off to a USB stick now.
    If you'll excuse a digression, Re 9200; I'm not sure why crap software would work fine for 3 years on a hard drive, then suddenly start corrupting indexes. I'm no expert but I'd suspect the old IDE disc is degrading before the judging the software - however good or bad it may be.
    It looks like I've missed the boat on HDR Fox T2 anyway.
  13. Black Hole

    Black Hole May contain traces of nut

    If you have a significant number of recordings, you will need a portable HDD rather than a UPD. Cheap enough.

    Obviously, but if you set the SCART output to RGB it should be pretty good (and tolerable while fault-finding).

    If you are sure the problem does not exist when the HDMI is disconnected, then yes. There is one very slight possibility that there is a renegotiation handshake happening on the HDMI interface which may cause a signal interruption (over the HDMI). To eliminate that, try connecting a different TV. A faulty Humax is not ruled out.

    The main problem with HDMI is the serial data over the HDMI generating interference which then couples to the aerial feed. This is particularly problematic at 1080. However, I would expect the symptoms to be a major obliteration of the TV signal, not occasional blips. You should be able to eliminate HDMI interference by using adequate TV patch leads - and the thicker type of cable with metal bodied TV connectors should be sufficient. As far as HDMI cables go, I have never known one to be any better than another, but "screened" would be good to have in the description.
  14. prpr

    prpr Well-Known Member

    I believe I said that in post #3.
  15. Black Hole

    Black Hole May contain traces of nut

    Having slept on this, really the reported symptoms do not correlate with HDMI interference or renegotiation. The reported strength and quality figures are well within limits.

    Intermittent interference from an external source is possible, and may not show up on a Signal Detection run (if it doesn't happen while watching), but should create a defect in a recording which is repeatable on playback.

    I am of the opinion that all the fiddling around is pointlessly trying to avoid a HDD reformat. You could try a factory default operation without HDD format first.
  16. Faust

    Faust New Member

    I have started having issues with audio and signal loss on my 2000T at lunchtime today. Started with my Sonos soundbar (uses optical all other devices played fine) no audio from 2000T whatsoever. I shut the machine down and rebooted. This time I got audio on BBC1 but on BBC News 24 HD or SD I thought I was listening to Norman Collier. This was then followed by picture freeze and a message about poor or no signal.

    Quick check showed strength to be 80% quality 100%. Flicked by to TV tuner, same channels played without any issue. I use a passive splitter not pass-through.

  17. Faust

    Faust New Member

    I have noticed the audio drop out/Norman Collier impersonation is now on all my HD channels from the 2000T with the exception of BBC1 & 2. No problem with Freeview HD from the TV tuner.

    Also getting weak or no signal message plus picture freeze despite strong signal?
  18. MartinLiddle

    MartinLiddle Super Moderator Staff Member

    So what are the signal strength and quality as reported by the Humax when watching an HD program?
  19. Faust

    Faust New Member

    Hi Martin,
    I have included signal strength in my original post i.e. Quick check showed strength to be 80% quality 100%

    Actually across the entire HD channel range it's 77% to 81% strength with quality 100%. This issue has only surfaced today. I did wonder if it could it be a transmitter issue but then why was there no issue from the TVs Freeview tuner?
  20. Faust

    Faust New Member

    All the issues of yesterday have now resolved. No audio breaks or picture freezes, signal strength and quality remains unchanged, go figure!