Hi,<br><br>(sorry to join your list and jump straight in with a bunch of questions!)<br><br>My MythTV setup with dual WinTV Nova DVB-T cards in it has started playing up recently. It has been working fine for many months, and I have not changed any hardware.
<br><br>The first symptom I noticed was that MythTV would report no data from card a LOT more often than it used to:I used to get the odd glitch (say one little woosh in about 10 programs), but now it does it every ten mins or so (sometimes more often). It always recovered after 4750ms (later I discovered by deliberately pulling the aerial that it takes 4750ms to recover from a small glitch). The net result is that the mpegs I save are so broken that almost all fail to go through mencoder (i encode TV for watching on my WM2003 cellphone on the train).
<br><br>I have gone back to tzap to try and get some diagnostics, but i am unsure as to the scale of the numbers it kicks out - as I understand it, these are uncalebrated values on an arbitary scale. Anyway, do these look like I have a signal problem? the values are very similar for both cards.
<br><br>status 1f | signal 3131 | snr eaea | ber 000000a1 | unc 00000000 | FE_HAS_LOCK<br>status 1f | signal 3131 | snr eaea | ber 000000b0 | unc 00000000 | FE_HAS_LOCK<br>status 1f | signal 3131 | snr eaea | ber 000000a8 | unc 00000000 | FE_HAS_LOCK
<br>status 1f | signal 3131 | snr ebeb | ber 000000b0 | unc 00000000 | FE_HAS_LOCK<br>status 1f | signal 3131 | snr ebeb | ber 000000a3 | unc 00000000 | FE_HAS_LOCK<br>status 1f | signal 3131 | snr eaea | ber 000000a5 | unc 00000000 | FE_HAS_LOCK
<br><br>As I understand it, so long as unc (uncorrected errors) is 0, the data has arrived in tact. I am a little worried about the signal of 3131 (assuming FFFF is the max), and the snr is lower than other examples I have pulled off the internet.
<br><br>Occasionaly while tzap is running, I get a line like the following (these are the output from grep, they dont appear one after the other in my log)<br><br>status 03 | signal 2d2d | snr 0000 | ber 0000ffff | unc 00000007 |
<br>status 03 | signal 2d2d | snr 0000 | ber 0000ffff | unc 00000000 |<br>status 03 | signal 2d2d | snr 0000 | ber 0000ffff | unc 00000006 |<br>status 03 | signal 2d2d | snr 0000 | ber 0000ffff | unc 00000000 |<br>status 0d | signal 2d2d | snr e9e9 | ber 000000b6 | unc 00000000 |
<br><br>This is I assume another manifestation of my problem.<br><br>I have made a list of what I think it could be, any thoughts would be welcome<br>1. Crystal Palace, UK transmitter has started broadcasting at a lower power or my aerial has become dislodged. I think this is unlikely (unless the numbers above indicate otherwise) as my non-pc STB receives freeview without a glitch, and a analog tuner on the same aerial displays a perfect picture.
<br><br>2. Software fault on my PC - unlikely as I have restored a known-good backup from before the 'troubles' onto a different HDD. Tonight I am going to install a clean FC4 install onto a brand new HDD to see if it has the problems.
<br><br>3. Hardware fault with my PC - <br>a) Ram - swapped with my Win32 box - no difference.<br>b) HDD - Moved the root partition to a spare HDD - no difference tonight I will try a new FC4 install on a new drive<br>c) Motherboard - Possible pci problems developed?
<br>d) Processor - I find it unlikely that the processor is not working and the machine in general is stable<br>e) DVB cards - unlikely as both behave the same.<br>f) Power supply - possible<br><br>lspci -vv displays a latency of 32 - is this normal? I read on this mailing list archive that some people were having trouble with the 1024byte DMA buffer overflowing - how would I know if this was happening?
<br><br>Ive also tried delibertately causing very heavy disk and network activity (by copying large .TS files around), and it doesnt seem to cause it to get any worse.<br><br>One other clue is that once or twice mythtv has reported IOBOUND errors - could this indicate that the ATA chips on my motherboard are faulty?
<br><br>If noone has any better ideas, my plan is as follows:<br>1. Fresh install of FC4 onto a clean hard disk in the same box<br>2. (if not fixed) Running that hdd on my win32 box, to eliminate EVERYTHING my side of the aerial
<br><br>Are there any handly Linux tools for diagnosing PCI problems? bear in mind that this is hardware that DID work before.<br><br>The machine in question has 4 ethernet cards in (one onboard), so the PCI slots are all full, but this has been the case for a long time.
<br>One more clue is that another (now unplugged) hdd has been behaving 'strangely' - once under Knoppix (with DMA turned off) it reported lots of errors (im afraid i forget the exact error (duh) but it implied it was failing to write during a dd if=/dev/zero of=/dev/hdd). I have since been unable to reproduce it
<br><br><br>Any help gratefully received :)<br><br>thanks<br>George<br>