[mythtvnz] Possibly dying tuner card? (or something else?)

[Rob Connolly]

Excerpts from Nick Rout's message of 2014-07-06 18:13:55 +1200:
> On Sun, Jul 6, 2014 at 6:08 PM, Stephen Worthington
> <stephen_agent at jsw.gen.nz> wrote:
> > On Sun, 06 Jul 2014 12:20:39 +1200, you wrote:
> >
> >>Hi All,
> >>
> >>I've been running my Myth setup for nearly 3 years pretty successfully,
> >>but recently I've been running into a lot of problems with failed
> >>recordings. This started out with almost all recordings on the
> >>MediaWorks multiplex failing, but it has since started occasionally on
> >>the other multiplexes too. From looking at the logs this looks like the
> >>adapter is unable to tune and eventually gives up. This appears to be
> >>more likely when another recording is already in progress. I've done a
> >>couple of retunes whilst this has been going on, but they didn't help.
> >>
> >>In the last week we have also started to get a lot of interferance on
> >>some recordings. Last night this produced a recording which was
> >>completely unwatchable due to picture degradation and sound blips.
> >>
> >>Looking in the log for this recording came up with something
> >>interesting:
> >>
> >>Jul  5 19:25:05 laforge  mythbackend[2881]: W DVBRead
> >>dtvrecorder.cpp:1290 (ProcessTSPacket) DTVRec(7): PID 0x3ec
> >>discontinuity detected (( 5+1)%16!= 7) 0.57985%
> >>
> >>This message is repeated 42677 times for this recording! Which fits with
> >>the almost constant picture issues. Aside from that myth completed the
> >>recording 'successfully', athough another recording which started later
> >>failed.
> >>
> >>Since the hardware and software didn't change since this was working,
> >>I'm wondering if this is caused by a slow failure of the TV tuner card,
> >>or some other part of the receiver setup (which consists of maybe 10m of
> >>cable to the antenna and a Kingray amplifier [with phantom power
> >>injected from ground level]). The other option is some real interferance
> >>- there is a ham radio operator in the next street who I've always
> >>suspected.
> >>
> >>The relevant details of my system are as follows:
> >>
> >>OS: Debian Wheezy with deb-multimedia packages for myth, etc.
> >>Tuner Card: Hauppauge HVR2200
> >>MythTV Version: 0.26.1+fixes20140227-dmo1
> >>
> >>I've uploaded the log from last nights recordings at
> >>http://webworxshop.com/~robert/logs/mythbackend.log.20140705. The
> >>recording 'Midsomer Murders' was the corrupted one, whilst the recording
> >>'Knowing' failed to tune.
> >>
> >>I'm going to try and do some investigation with tzap later today and I'll
> >>post the results here.
> >>
> >>Please let me know what you guys think.
> >>
> >>Thanks in advance,
> >>
> >>Rob Connolly
> >
> > When one mux is giving problems, or gives more problems than the
> > others, that usually indicates reception problems, rather than tuner
> > problems (unless, like me, you have muxes forced to use specific
> > tuners).  Usually one mux has the worst signal, either the lowest
> > power transmitter, or the highest frequency.  So that mux is the one
> > that gives problems first.
> >
> > I would suspect the cabling first.  Are you using good shielded aerial
> > cable (RG6 I think is what is best), and F-connectors everywhere you
> > can?  Is there somewhere that another power or signal cable has been
> > installed or moved to that runs parallel near your aerial cable?  Has
> > a cable been bumped and pulled out partially anywhere (eg while
> > vacuuming)?
> >
> > Check that the power supply to your aerial amplifier is still working
> > - they are usually just wall warts and hence not usually the most
> > reliable of things.  Visually check that the aerial itself is OK and
> > still pointing in the correct direction.
> >
> > Try using LiveTV and see what the on-screen signal level and s/n
> > values show, or use dvbtune.  This is the command line I use for
> > dvbtune:
> >
> >   dvbtune -f $a -qam 64 -gi 16 -cr 3_4 -bw 8 -tm 8 -m -c $ADAPTER
> >
> > where $a is the frequency in kHz (530000, 562000, 578000 or 594000 for
> > Wharite), and $ADAPTER is the adapter number, which is 0 or 1 in your
> > case.
> >
> > Do you have another DVB-T tuner you could plug in for comparison (eg
> > USB one on your laptop)?
> 
> 
> All good points, the other one is that your antenna could have
> shifted. High winds lately? Earthquakes? Similarly a good storm could
> get H20 into your cabling.
> 

The fix for which is presumably new cabling?

*Sigh*

Cheers,

Rob