Bizarre problem - PVR turns itself off during scheduled recordings!

[siliconaudio]

I have refrained from posting this for a few days until I was sure I wasn't doing something stupid or going mad.

Here's the problem - if I schedule recordings, I come back and find that my PVR has shutdown completely. Not in standby or hybernation - the PC is off.

This never happened for a year of running GBPVR and the PC is set to go into standby when it's not in use - which it does successfully.

I might get 15 minutes of the recorded show, but that's it. I have never seen this PC shutdown before, and I can watch TV for days and it never happens. It seems it must be recording for it to happen.

I can find nothing in Windows event logs and nothing of real interest in NPVR's logs. What on earth could be happening here?!?!

[whurlston]

Check your CPU shutdown temp in BIOS. Also blow out any dust from the CPU heatsink fins (which can cause the CPU to not cool as well as it should). Strange that it happens with recording and not playback though (which would heat the CPU more than recording would).

[siliconaudio]

Check your CPU shutdown temp in BIOS. Also blow out any dust from the CPU heatsink fins (which can cause the CPU to not cool as well as it should). Strange that it happens with recording and not playback though (which would heat the CPU more than recording would).

I keep this PC clean and the fans are clear and working. Plus, it's winter here and pretty cold at the moment. The PC never misses a beat and the problem started with NPVR. Again, it is only recording that triggers this. In the NPVR logs, I can see that the PC wakes for record, but at some stage turns itself off. I can have this PC running for days with no problems, watching TV, whatever. I'm certain this is a NPVR issue.

[sub]

Thats a new one on me. There is certainly no code in NPVR that would tell your PC to shutdown. You must have Windows configured to do this or something similar.

[johnsonx42]

It's some sort of hardware or driver error that's making the PC shutdown. Yes, I understand it doesn't do it *any* other time, but that doesn't change the diagnosis. If you don't see a bunch of shutdown messages in your system event log (and I'm betting you don't, rather you see pretty much nothing going on and then a bunch of startup messages when you turned the computer backup on), then your computer had a sudden shutdown. These are caused by power-supply problems, heat problems, memory problems, driver problems, etc. Again, yes, I understand it doesn't do it *any* other time, but that doesn't change the diagnosis.

The first and simplest thing to do would be to get Memtest 86+ 4.00 (http://www.memtest.org) and let it run a couple of full passes on your system.

[speising]

wouldn't it reboot/bluescreen rather than shut down in such a situation?

[johnsonx42]

sometimes yes, sometimes no. it depends on the exact nature of the problem.

[siliconaudio]

It doesn't seem to be a problem if I'm watching one channel while recording another. It seems that if the PC wakes from standby to record, it will turn itself off sometime after that. I'll run some diags on the system. I did go from 2 GB to 4 GB around the time of moving from GBPVR to NPVR, so the memtest idea is a good one.

Thanks guys.

[johnsonx42]

You may also wish to inspect your mainboard for failing capacitors. I've seen boards with bad caps do this as well.

Here's a photo showing what to look for: http://www.thenakedpc.com/dan/Bulging_Ca...ose-up.jpg
All capacitors should be flat on top; any bulging, even with no leaking, is bad.

[siliconaudio]

All the electrolytics look fine (I was an electronics tech for many years). The PC is generally very stable. The only time this problem has ever occurred is when un-attended recordings wake the PC from standby. The only changes made to the machine preceding this problem were NPVR and an upgrade from 2 GB to 4 GB of RAM. I will pull the new RAM out and soak-test for a few days to remove the first variable.