TV Signal disappears but only while recording

B

Brid

Forum Supporter
Hi All,
I have an HDR -Fox T2 with custom software and all has been great for years but recently while browsing channels the signal has been so bad it is unwatchable. I thought it was a problem with the aerial or the aerial cable had been unplugged but after some experiments I have found that this only occurs in this room and only while the Humax is recording. Once I tell it to stop recording all is OK on the other channels, for instance last night I was recording just the Quest channel and the other channels I browsed were unwatchable until the Quest program was recorded.

Do you think it has developed a hardware fault?

Thanks
 
Your first port of call should be to look at the HDD diagnostics. If the HDD or the file system is in trouble, the OS has to retry accesses and this adds a lot of processing load with the possibility of interrupting high-priority tasks.

See whether WebIF >> Diagnostics >> Disk Diagnostics reveals anything, and you can usefully follow that up with fixdisk (via WebIF >> Diagnostics >> Command Line [if you have webshell installed], or using Telnet). Report what you find.

Other than that, use the tuner tests available on the hidden service menu (see Things Every... section 9) to confirm there's not actually something wrong with the signal or tuners.
 
Brid said:
after some experiments I have found that this only occurs in this room and only while the Humax is recording.
Click to expand...
Just for clarity, are you saying you've tried recording and viewing simultaneously with this machine in another room and it works properly?
 
I am running the tests at the moment suggested and will post the results.
I didn't explain that very well but I have 3 other TVs and another 2 x humax's (same model) in other rooms on the same aerial and none of those are giving a problems so it has to be something to do with the Living Room humax (the one I opened the post about) .

Hope that helps but anything I haven't explained correctly please just ask
 
What is the system doing when recording that it isn't doing otherwise?
1. Writing continually to two files on partition 2 (or one if Time Shift Recording is disabled).
2. Using both tuners if the recorded show is on a different mux from the live channel.
 
I think the hard drive looks OK and both tuners are showing 100% quality and 82% signal on both . I just did another test by just pressing record on bbc1 and this then "lost" itv1 and ch4 with a message saying that the signal was too low. As soon as I stopped recording bbc1 the other channels of itv1 and ch4 same straight back on fine.

Details in the attachment, any ideas appreciated
 

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  • fixdisk results.pdf
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i'm no expert at all but it all looks OK so the only thing I can thing of at the moment is the tuner is faulty perhaps?
 
Sounds good then hopefully? No problem with sending the Disk Information report but could you help me with how to do that? Is it this bit??

1674748367480.png
 
Also, perhaps try the option to run the long SMART test using the -l (ell) fix-disk option.

Otherwise, maybe this is some kind of power limitation that could result from a bad capacitor.

Each tuner also has a demodulator with its own on-board regulator and accompanying potentially failing capacitor. Possibly, the tuners could both be reporting OK but one of the demodulators could be sending corrupt streams into the AV processor of the SoC.
 
Are you viewing TV using the Humax to control which channel is selected for viewing or are you using the TV remote and the TV tuner using the aerial passthrough from the Humax

Can you successfully record two programmes at the same time?
 
MartinLiddle said:
Fixdisk found some minor corruption in the file system but nothing to worry about. Please could you show us the rest of the Disk Information report?
Click to expand...
What we to see is the table of results; your post #10 just shows the bottom of the table. It looks to me as though you are using a hard drive that isn't optimised for PVR usage.
 
Brid said:
Sounds good then hopefully? No problem with sending the Disk Information report but could you help me with how to do that? Is it this bit??

1674756215614.png
Click to expand...
There are about 20 more lines just before those.
 
/df said:
Also, perhaps try the option to run the long SMART test using the -l (ell) fix-disk option.

Otherwise, maybe this is some kind of power limitation that could result from a bad capacitor.

Each tuner also has a demodulator with its own on-board regulator and accompanying potentially failing capacitor. Possibly, the tuners could both be reporting OK but one of the demodulators could be sending corrupt streams into the AV processor of the SoC.
Click to expand...
I have not replied because the long smart test takes forever and I cancelled it in the end. The second part of your post sounds possible to be honest which would mean that it isn't possible to fix
 
MymsMan said:
Are you viewing TV using the Humax to control which channel is selected for viewing or are you using the TV remote and the TV tuner using the aerial passthrough from the Humax

Can you successfully record two programmes at the same time?
Click to expand...
Yes only a problem when viewing through the Humax and now I have stopped the long smart test I just confirmed that I lose ITV while recording BBC1 BUT while recording BBC1 I can switch to the built in TV tuner and ITV is fine
 
MartinLiddle said:
What we to see is the table of results; your post #10 just shows the bottom of the table. It looks to me as though you are using a hard drive that isn't optimised for PVR usage.
Click to expand...
I suspect you are correct about the hard drive not being optimised for a PVR but on the other hand this hard drive has been in it and working OK since well before lock down so probably about 3 - 4 years now
 
Luke said:
There are about 20 more lines just before those.
Click to expand...
I didn't send the rest of the screen shot as I wasn't sure that this was the correct thing to post ? here is the complete story so to speak in 3 screen shots , I hope there is something in there that gives some clues

1.png2.png3.png
 
MartinLiddle said:
It looks to me as though you are using a hard drive that isn't optimised for PVR usage.
Click to expand...
Yes, that's a desktop drive. It would be useful to check the alignment is correct by running the 4kalign diagnostic (which I've just found out doesn't work properly if you have virtual-disk2 installed, or maybe it's opkg-beta, or a combination thereof).
MymsMan said:
Can you successfully record two programmes at the same time?
Click to expand...
Agree that is a useful test.
Brid said:
I just confirmed that I lose ITV while recording BBC1
Click to expand...
Are you talking about SD? These are on different muxes. What about HD where they're on the same mux? You need to be more precise with names (quote the LCNs as well).
You need to consider all the combinations to pin down what's going on.
 
Last edited:
Yes, that's a desktop drive. It would be useful to check the alignment is correct by running the 4kalign diagnostic (which I've just found out doesn't work properly if you have virtual-disk2 installed). Sorry I will need to look up how to run 4kalign as I have never done that before and I don't know what virtual disks are sorry

Can you successfully record two programmes at the same time? Sorry missed this one and when I record 2 programs at the same time it does record but one of them just has so much signal loss that it is un watchable

Are you talking about SD? These are on different muxes. What about HD where they're on the same mux? You need to be more precise with names (quote the LCNs as well).
You need to consider all the combinations to pin down what's going on. That test was on SD yes and I have just pressed record on BBC1 HD and found that I can view any other HD channel fine through the Humax but I can not view any SD channels while recording BBC1HD. The TV tuner still works fine what ever the Humax is doing. I am trying to be as specific as I can but I am obviously not as knowledgeable or as technical as you and I appreciate any help I can get but I don't know what a Mux or LCN is
 

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