Tuner failure?

Richard Hankins

New Member
Folks,

my HDR Fox T2 is showing the following symptoms:
  • two weeks ago, I started getting blocky pictures and bits of recordings missing, suggesting a dodgy TV signal (but the TV itself is fine);
  • one week ago it was worse with just a hint of a picture now and then;
  • I then did an auto retune, and it could find no TV signals at all.
  • Now it just says "no channels - press OK to search" (or something like that). I press search and it still find no channels (though the TV is receiving just fine, so the feedthrough is working OK)
I've searched this forum for anyone reporting anything similar but found nothing - but still hoping someone has seen this before and has discovered a cure.

The unit is playing back recordings from its HDD just fine, and the remote is working as expected.

I've done some internal checks. The power supply voltages look reasonable:
  • 12V rail reads 12.25V
  • 5.8V rail reads 6.6V
Power feed to hard disk drive has 5.0 and 12V on it, so that's fine.

Taking out the main board shows no obvious failures, nor can I spot any dodgy connections on the two TV tuners where they are soldered into the board. I've tried the so-called "service menu" but that's so limited as to be useless.

Anyone seen this before - and have any ideas? Does the custom firmware offer any hardware troubleshooting?


thanks

Richard
 

Trev

The Dumb One
I guess that you must have tried double checking the quality/strength of the aerial input and the condition of any patch leads to eliminate them?
 

Black Hole

May contain traces of nut
The first port-of-call (prior to measuring voltages etc) should have been a factory reset:

Menu >> Settings >> Installation >> Factory Default
 

MartinLiddle

Super Moderator
Staff member
There certainly have been reports of tuner failure in the past and I don't recollect anybody ever having fixed a broken tuner.
 

Ezra Pound

Well-Known Member
It is possible to test each of the two tuners separately, you need to enter the Hidden Settings Menu (Details HERE), then go to Signal Detection, this will give the option to select Tuner 1 or Tuner 2 and see Signal strength and signal Quality for any selected Transponder (MUX)
 

prpr

Well-Known Member
Transponder is not a term associated with the technology involved in terrestrial broadcasting.
 

Ezra Pound

Well-Known Member
prpr : Transponder is not a term associated with the technology involved in terrestrial broadcasting
You had better tell Humax that then, that is why I also used (MUX) in the explanation

hidden.jpg
 
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Richard Hankins

New Member
Thanks for all the helpful comments everyone.

@Trev: I am assuming that there is no signal strength issue, because the TV signal comes in via the Humax, and loops out again to the TV. And the TV shows no sign of signal strength problems whatsoever.

@Black Hole: yes, I'm going to do a factory reset next. I only checked the voltages because I had the lid off and a DVM handy. I initially assumed it was going to be something easy - like a broken solder joint on the TV signal wiring - which is why I started looking at the internal hardware.

@Ezra Pound: yes, I discovered the tuner selection menu you describe. What's less obvious is which channel the tuners are tuned to, when you do the test. I assume its the one shown in the higher level menu. I had that set to a channel with a known signal on it. And both tuners showed zero signal strength when I did the test. Its highly unlikely both tuners would go faulty at the same time. So that suggests its a fault in a bit of common circuitry - such as a power supply - or some signal processing elsewhere on the main board.

Hardware is pretty reliable these days, so a factory reset is the next thing to do. I will update this thread when I have done it.


Richard
 
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Richard Hankins

New Member
An update. I have done a factory reset and its made no difference at all. I didn't choose to format the HDD. I assume there is nothing on the HDD other than recordings - no files related to the OS I assume? Is that correct?


Richard
 

Ezra Pound

Well-Known Member
What's less obvious is which channel the tuners are tuned to, when you do the test.
The Tuner is set to a UHF Frequency e.g. 618MHz in the picture above, for digital TV this carries a Multiplex (or MUX), In turn a MUX contains a number of TV channels (31 for my 618MHz), there is a list HERE ( select Show = everything, Select by = Mux, List). I currently have 8 Muxs carrying 129 TV, Radio and Data channels, but what you need to remember is that the Tuners select a MUX rather than a TV channel
BTW
The Hard disk does hold some other stuff apart from recordings, but I don't think formatting it will help with your tuner problem
 
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Richard Hankins

New Member
Well, the HDR certainly works with the old channel numbers - albeit they now carry MUXes as you say. We just have some confusion over the meaning of the word "channel" - which you are applying to mean a single program (such as "BBC1"). I am referring to the carrier frequencies, which have always been numbered 21 - 68 in the UHF band.

Either way - my own HDR is refusing to receive anything on any channel number I have tried. Anyone every managed to source the main board as a spare from anywhere?

Richard
 

MontysEvilTwin

Well-Known Member
Humax will sell you a mainboard if they have stock, but it might not be much cheaper than getting it repaired by them. You could buy a second-hand unit off eBay for parts or as a replacement. If you have not done so already, any recordings you want to keep will need to be decrypted before changing the mainboard.
 

Black Hole

May contain traces of nut
I have done a factory reset and its made no difference at all. I didn't choose to format the HDD. I assume there is nothing on the HDD other than recordings - no files related to the OS I assume? Is that correct?
Nothing that matters from this point of view. The factory reset was admittedly a long shot, but could potentially have refreshed some hardware parameters set at boot time, is a simple thing to try as a first step, and is what Support would ask you to do by default anyway.
 
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