17 replies to this topic

[adante]

Does anybody have any experence with faulty/failed Visionplus DVB-T cards??

I was running a very happy mythtv setup with three visionplus DVB-T cards off a single rabbit ears antenna. The setup was pretty dodgy but it worked fine. The cards are about 1.5 years old (sadly, out of warranty)

Some time ago after a rainy spell, the whole system fell down. After 20+ hours of software rebuilding/reconfiguration and antenna fiddling, I've come to the conclusion that 2 of the 3 cards appear to have broken somehow.

Basically, while they show acceptable signal/SNR, when trying to actually use them to watch TV they produce a signal of variable quality. This can be from absolutely unwatchable colour soup where you can make out anything except blurs, to a distinguishable picture with varying levels of interference, through to working perfectly fine. This usually varies from channel to channel and is not fixed, (although usually 7 is good and 9 is stuffed). I am pretty sure this is a card problem because the 'working' card can use the exact same antenna input and work fine.

Anyway, the fact that some channels still work perfectly give me hope that I can somehow fix these cards instead of chucking them in the trash. So I was wondering if anybody had run into this sort of thing before, and if they were able to do anything about it.

cheers

[joeybloggs]

Done the obvious things ? Checked the center connectors of the socket. Carefully prised the top off the tuner can and checked that the center connector to the tuner pcb is intact. IIRC a couple of people had problems with fatigue cracking ~

[adante]

joeybloggs, on Apr 22 2006, 08:10 PM, said:

Done the obvious things ? Checked the center connectors of the socket. Carefully prised the top off the tuner can and checked that the center connector to the tuner pcb is intact. IIRC a couple of people had problems with fatigue cracking ~

hmm, i've checked the centre connectors of the socket, tightened them up a bit with pliers, and pried the top off - according to my multimeter the centre connector is still attached to the pcb

nothing else looks out of place in there, but I wouldn't really know if it was

[darkfalz]

And rescue my daughter!

[digitaladvisor]

adante

Well considering the whole idea in using Rabbit ear antennas are not really stable - maybe its time to use proper frequency rejecting antenna pick ups.

You see all it takes is some new broadcasted wave form in the  environment or fixed weather pattern and it sinks.

"perfect one day but lost the next"

DA

[adante]

digitaladvisor, on Apr 22 2006, 10:11 PM, said:

adante

Well considering the whole idea in using Rabbit ear antennas are not really stable - maybe its time to use proper frequency rejecting antenna pick ups.

You see all it takes is some new broadcasted wave form in the  environment or fixed weather pattern and it sinks.

"perfect one day but lost the next"

DA

well, I am no longer using rabbit ear antennas but something similar to this http://www.radiopart...roduct=00720351 with an active 4-way splitter. I also picked up some digital filter thing but it seemed to make things worse as opposed to better.

I'm not very familiar with all this antenna stuff though, but I basically assumed that this was not an antenna problem due to the fact that one of my cards works perfectly with the antenna (or even the bunny ears) while the other 2 do not. Could you explain why this would not be the case?

[digitaladvisor]

adante, on Apr 22 2006, 10:20 PM, said:

well, I am no longer using rabbit ear antennas but something similar to this http://www.radiopart...roduct=00720351 with an active 4-way splitter. I also picked up some digital filter thing but it seemed to make things worse as opposed to better.

I'm not very familiar with all this antenna stuff though, but I basically assumed that this was not an antenna problem due to the fact that one of my cards works perfectly with the antenna (or even the bunny ears) while the other 2 do not. Could you explain why this would not be the case?

If you amplify rubbish waves from antenna type you increase mixture into the amped signal.

Good antenna are designed to accept and reject certain band levels on the UHF/VHF levels. Sometimes in rare ocassions filters are used at the antenna to reject signals still being recevied.

DA

[Ricbec]

digitaladvisor, on Apr 23 2006, 05:46 PM, said:

If you amplify rubbish waves from antenna type you increase mixture into the amped signal.

Good antenna are designed to accept and reject certain band levels on the UHF/VHF levels. Sometimes in rare ocassions filters are used at the antenna to refect signals still being recevied.

DA

I think you's are missing the point of what adante is trying to say - he has 3 (three), visionplus cards that were working perfectly fine with a dodgy set-up - 2 have all of a sudden began playing up, while the third one is fine........if one works fine and the other 2 dont with the same setup on the same day with the same conditions, it can pretty much only be something with the 2 other cards....(sorry, but im not a DTV on the PC buff anymore, far too many hassles for my liking, regardless of the brand of card, so unfortunately, i do not have any constructive advice for you adante)

[bpanther]

Adante,
Try 1 VisionPlus card at a time.  Try a local rabbit ears antenna to verify that it is not a problem in your antenna or distribution amplifier or feedlines.
Are you certain that the active distribution amp gets power?  (In our house, people tended to switch off the power socket feeding the Amp, required a permanenet tape and sign on the switch...).
If you have another set top box or DVB-t card, try that with the antenna feed to your mythTV box, see if the RF signal there is sufficiently strong and clean.
Is it possible that your antenna has moved (you mentioned that the problem started after some wet weather)?  DVB-t is much more 'fussy' than analogue TV to antenna pointing, reflections etc.

Running a 2 VisionPlus system here with webscheduler, without any problems regarding the DVB-t cards directly.

Cheers,
Bpanther

[adante]

bpanther, on Apr 23 2006, 07:36 PM, said:

Try 1 VisionPlus card at a time.  Try a local rabbit ears antenna to verify that it is not a problem in your antenna or distribution amplifier or feedlines.

I have tested each card individually with the following setup:
Remove all but one visionplus card from the box. Plug the antenna in directly, and attempt to watch video.

The results are as following
One card works fine
Two cards do not an exhibit the symptoms I described in the OP.

I have also tried different antennas including the original rabbit ears and the results are the same as above.

Hence, I am fairly certain that the problem is resulting from some sort of inherent difference in my cards.

Ricbec, on Apr 23 2006, 07:03 PM, said:

I think you's are missing the point of what adante is trying to say - he has 3 (three), visionplus cards that were working perfectly fine with a dodgy set-up - 2 have all of a sudden began playing up, while the third one is fine........if one works fine and the other 2 dont with the same setup on the same day with the same conditions, it can pretty much only be something with the 2 other cards....(sorry, but im not a DTV on the PC buff anymore, far too many hassles for my liking, regardless of the brand of card, so unfortunately, i do not have any constructive advice for you adante)

That's pretty much or less right. Maybe I didn't explain it very well so thanks for clarifying Ricbec.

digitaladvisor - while I understand the antenna aspect is very important, I am pretty sure my antenna is not contributing to the problems I have described, unless you can explain to me why the issues you describe would have this effect on specific cards but not others.

[renura]

Quote

The results are as following
One card works fine
Two cards do not an exhibit the symptoms I described in the OP.

Adante, if they are identical cards and one works fine, whereas others don't using the exact same setup, then I would say something may have been damaged and I am not sure that there is anything that you can do about it. Best thing to do is to replace them.

[vadimz]

I've read on these forums of people updating card's flash roms. So maybe yours got corupted somehow.
Do a search here for that...

Vad.

[myrantz]

adante, on Apr 22 2006, 07:51 PM, said:

Does anybody have any experence with faulty/failed Visionplus DVB-T cards??

I was running a very happy mythtv setup with three visionplus DVB-T cards off a single rabbit ears antenna. The setup was pretty dodgy but it worked fine. The cards are about 1.5 years old (sadly, out of warranty)

Some time ago after a rainy spell, the whole system fell down. After 20+ hours of software rebuilding/reconfiguration and antenna fiddling, I've come to the conclusion that 2 of the 3 cards appear to have broken somehow.

Some questions, what's your?
1) Linux distro
2) Mythtv version
3) kernel version (and if you are using DVB drivers from the kernel or you compiled your own).

Some things you can try (in no particular order):
1) Download and build CVS version from Linuxtv.org, that may help.
2) Do a rescan of your channels in mythtv. If that doesn't work, look through all your channels and make sure all the settings are "scanned" correctly.
3) run mythbackend with "-v channel,siparser" option and see what the logs says
4) run mythfrontend with "-v playback" option and see what it says.
4) Update your version of mythtv if possible.
5) I assume you have the same problems when watching DVB channels with kaffeine/xine?
6) Run dmesg and check /var/log/messages and see if there are any problems.

It may be only my system, but I can't get my Twinhans to work with kernels 2.6.11, 2.6.13 and 2.6.15 (all odd numbers somehow). If your kernel starts with these numbers, update or downgrade. I'm using 2.6.16.9 now and it works relatively well...

[hoolaparara]

treblid, on Apr 24 2006, 10:49 AM, said:

It may be only my system, but I can't get my Twinhans to work with kernels 2.6.11, 2.6.13 and 2.6.15 (all odd numbers somehow). If your kernel starts with these numbers, update or downgrade. I'm using 2.6.16.9 now and it works relatively well...

  Definitely your system, I have a VP card and went from 2.6.7 -> 2.6.13 -> 2.6.15. Currently happily using 2.6.15 with the Visionplus and a Kworld. (Of  course the big jump is because I couldn't even get the damn computer to boot anything from 2.6.9 until the the 2.6.13 so YMWV).

  As for the original poster, the suggestion of corrupt firmware would seem to be about the only reasonable fixable chance, otherwise I'd be thinking the cards got done by power fluctuations or something. Perhaps a enforced opportunity to get some nicer cards.

[adante]

vadimz, on Apr 24 2006, 09:56 AM, said:

I've read on these forums of people updating card's flash roms. So maybe yours got corupted somehow.
Do a search here for that...

Vad.

Can someone help a dumbo out and throw some links my way? I've tried doing a form visionplus firmware on this forum but just got links to all sorts of visionplus stuff (couldn't find anything specific to firmware).

A google search reveals a fair bit of talk about firmware but I can't actually seem to locate it. The twinhan download site (http://www.twinhan.c...er&software.asp) doesn't list any explicit firmware, I've tried looking inside the DVB-T PCI file but haven't found anything that looks remotely like a firmware upgrade.

cheers

[vadimz]

It was actually from another forum here...

http://forums.dvbown...?showtopic=1482

Vad.

[adante]

vadimz, on Apr 26 2006, 04:18 PM, said:

It was actually from another forum here...

http://forums.dvbown...?showtopic=1482

Vad.

Well, it was a long shot but it seems to have paid off - sort of.

With the the link you provided, I threw the 2 'broken' cards into my windows PC and ran the e2prom program.

Anyway, on both of the cards the first 8 bytes of eeprom were different from what bear posted. I can't remember exactly, but the first broken card was off (something like 05 FF FF FF FF FF FF FF), and the second card was totally blank (FF FF FF FF FF FF FF FF). (Just FYI, from the original post it is supposed to be 05 00 00 00 00 00 00 FB FF). Anyway, it got a little wierd, because after updating the first card, I put it back into the linux box and it worked right off the bat, so I thought, sweet!

With the second card, when I put it into the linux box, it completely failed. Linux was unable to identify/use the device (dmesg didn't recognize the ids). LSPCI -v showed the device was showing up with the right id's (interestingly this card was a 036E, while the other two were 0878) but linux didn't like it. Anyway, I put it back into my windows box and ran e2prom again to verify I hadn't made a mistake. It looked all right, but just on a whim I blanked the eeprom (set it all to FF, including the last 4 bytes), and then set it appropriatelly. Then I ran the twinhan software to check to see if the card was detecting ok, and it seemed to be (unfortunately I don't have any antenna access where my windows box is, so couldn't actually test it there).

After throwing it back into my linux box.. it was all sweet. Everything seems to be working fine now, and all 3 cards can record simultaneously.

In retrospect I have to admit it's an odd situation. If the eprom changes did actually have some effect, I'm surprised the cards could work at all with it being scrambled. I also suspect the third card is on it's last legs, so I won't be too surprised if it up and dies on me in the near future.

Of course this is not the first time I've had 'firmware' problems with the Twinhans. When I originally bought these and was setting them up, once they went into some sort of freeze. After 2 hours of module fiddling and kernel recompiling, and it turned out all that was needed was a cold-boot (I'd just been hitting the reset switch).

Anyway just wanted to let you guys know what happened and say thanks a lot for the advice. I knew it was a long shot when I asked but I'm happy to be able to get some more use out of these 2 cards

[vadimz]

Well I'm glad you got it sorted... sort of  

Vad.