Problem locking on to a tuner?

[time_lord]

Hi, I've had a problem for a while, it seems like NPVR often cannot get or lock on to a tuner when I try to watch live TV. I have an HVR-2200 (dual tuner).
For example I click on a channel to view, and the screen is just black. I press escape and repeat, and sometimes it works correctly on the 2nd attempt, but it can take 4 or 5 goes.
Another situation is I'm watching live tv just before 6pm, and a dialog pops up to tell me there isn't a tuner available to record the 6pm news... but I have a dual tuner card. (And if the 'live tv' is buffered and I'm a few minutes behind, after I dismiss the message I've lost the remains of whatever I was watching :-( )

I removed all channels from both tuners, re-tuned one, then exported the channels from the first tuner and imported into the second. The setup and also NPVR device status both show 2 tuners.
Any idea what could be going wrong? Maybe a complete uninstall/reinstall is needed to clean up whatever is wrong, but I don't want to lose all my current recordings. It seems less reliable in the last few weeks and I don't know if that's because of recently installing 4.2.5 or re-tuning.

So yes I'm currently running NPVR 4.2.5... I briefly looked at installing 5 but I got the impression it would not be a 5 minute job to retain all my current recordings (maybe I'm wrong about that) so I thought I'd stick with the old.
Also I doubt this is a factor, I have no spare disk for recording, but my system has been full for a couple of years(!) and live tv still works once it 'locks in'... my tuner problem has only been occurring for the last 2-3 months.
[DVB-T, Wgtn/Kaukau]

[Graham]

For example I click on a channel to view, and the screen is just black. I press escape and repeat, and sometimes it works correctly on the 2nd attempt, but it can take 4 or 5 goes.
...
So yes I'm currently running NPVR 4.2.5... I briefly looked at installing 5 but I got the impression it would not be a 5 minute job to retain all my current recordings (maybe I'm wrong about that) so I thought I'd stick with the old.
Also I doubt this is a factor, I have no spare disk for recording, but my system has been full for a couple of years(!) and live tv still works once it 'locks in'... my tuner problem has only been occurring for the last 2-3 months.
[DVB-T, Wgtn/Kaukau]

Recreate the black screen problem and attach logs to a post telling us the time that it happened.

Migrating from V4 to V5 might take as long as two or three minutes ... https://github.com/sub3/NextPVR/wiki/upd...on-Windows

Make copies of config.xml and npvr.db3 before you begin so that you can be sure that you can go back.

[sub]

Yeah, we'd need to see logs.

[time_lord]

Thanks guys - I couldn't see anything wrong in the logs (i.e errors), but it might be what isn't there that is the key.
Will look at getting logs soonish... might be after NY now. Cheers

[time_lord]

Hi, find attached logs (I should've done this b4 xmas!)

So I exited NPVR and stopped the service, then cleared logs folder. Started service at 17:29 and NPVR. From TV Guide dbl-clicked TV2, and it was a little sluggish but started playing ok. Escaped, went to TV2+1... went back and forth a couple of times, all working.

Then tried TV1 ('The Chase') at 17:31, and screen was blank; waited a few seconds and nothing was happening, so hit escape. Tried twice more, same thing. On the 4th try, TV1 came up ok and all is well.
This is a pretty typical behaviour and happened a few minutes earlier with TV2 (before I stopped things and cleared logs).

Hope this helps id the problem!

[Graham]

So I exited NPVR and stopped the service, then cleared logs folder. Started service at 17:29 and NPVR. From TV Guide dbl-clicked TV2, and it was a little sluggish but started playing ok. Escaped, went to TV2+1... went back and forth a couple of times, all working.

Then tried TV1 ('The Chase') at 17:31, and screen was blank; waited a few seconds and nothing was happening, so hit escape. Tried twice more, same thing. On the 4th try, TV1 came up ok and all is well.
This is a pretty typical behaviour and happened a few minutes earlier with TV2 (before I stopped things and cleared logs).

The ndigitalhost log has this ...

2021-01-08 17:29:45.985 [DEBUG][5] locked=1, present=1, strength=-16, quality=100  (took 79ms to check)
2021-01-08 17:29:45.985 [DEBUG][5] About to tune BDA graph:
<tuning>
  <type>DVB-T</type>
  ...
  <provider>TVNZ</provider>
</tuning>
...
2021-01-08 17:29:45.993 [DEBUG][5] DigitalRecorderDVBT::Tune@5
2021-01-08 17:29:46.724 [DEBUG][5] DigitalRecorderDVBT::Tune@post
2021-01-08 17:29:46.737 [DEBUG][5] Calling LockChannel()
2021-01-08 17:29:46.830 [DEBUG][5] locked=1, present=1, strength=-16, quality=20  (took 93ms to check)

The variation in the "quality=" value appears repeatedly and suggests a signal quality isssue.

What  happens if you do a test with cable splitters and extension coax cables removed from the aerial lead?

[time_lord]

Yeah fair call, I will have to move stuff to check cables etc, but I'm not sure that is the problem. Once again I have just cranked it all up and there were 3 failed goes at getting TV1 to come up, and the 4th time worked. It seems too... predictable?

2021-01-09 17:45:47.912 [DEBUG][16] locked=1, present=1, strength=-20, quality=100  (took 62ms to check)
2021-01-09 17:46:19.710 [DEBUG][18] locked=1, present=1, strength=-16, quality=100  (took 62ms to check)
2021-01-09 17:46:27.968 [DEBUG][18] locked=1, present=1, strength=-16, quality=100  (took 78ms to check)
2021-01-09 17:46:28.781 [DEBUG][18] locked=1, present=1, strength=-4, quality=25  (took 93ms to check)

And in this case the logging says quality 100 (when it was failing to work) and quality 25 when it did work.
It's the strength all other the place (is that in db?)

[Graham]

And in this case the logging says quality 100 (when it was failing to work) and quality 25 when it did work.
It's the strength all other the place (is that in db?)

The tuner tells NextPVR that the strength and quality have those values at that moment and NextPVR writes a messsage to the log ... the values are not stored elsewhere ...  There is no standard set of values that applies to all tuners ... tuners from the same manufacturer might use different values to indicate indentical conditions.

But ... the variation in values merits investigation to try and find a reason why the values vary ... it is the variation rather than the absolute values that is of interest ... You are getting variable results when you make recordings ... the only thing that appears to be varying is the signal from the coax ... therefore ...