Random Shutdown

[maxximilian]

Bit of a puzzler here. HP Pavillion quad core machine a couple years old. Runs everyday for about 12-14 hours....never had a problem. Recently it started shutting down randomly. Sometimes once a day....sometimes several times. Please note....this isn't a hard shutdown where the thing just goes black. It runs the shutdown procedure on it's own, complete with shutdown screen. And when you restart....there is no mention of an error or improper shutdown.

Cracked the case....cleaned out the dust in case it was a heat issue....and also placed a room fan on the floor directed inside the case. No effect.....random shutdowns still occur. Also tried turning on the machine and just letting it sit with nothing running....still would get shutdowns. There doesn't appear to be any pattern. Sometimes no shutdown after running all day. Then another time it might shutdown after only an hour.

No updates or installs prior to problem starting about a week ago. Two malware scans say I am clean. Also not hearing anything like a fan bearing going or even fans speeding up.

Any ideas?
Could a hardware issue produce a clean, soft shutdown as opposed to just going black?

If not hardware.....what else?

[SuperSparks]

The Power Supply going bad will cause that. Or, more unusually but with the same symptoms, something that is causing an intermittent short circuit inside the tower can cause enough voltage drop on a rail to cause a reset.

[maxximilian]

Hmmmm.....interesting. I was always under the impression that hardware or power problems would cause a hard shutdown....just go black. And not run the windows shutdown sequence....

Any ideas on how to confirm a hardware issue? As I say....when I restart, windows doesn't give me any indication there was even a random shutdown.

[jdc2000]

If you have a decent spare power supply, substitute that for a day or two to see if the problem clears up.

[maxximilian]

No spare power supplies. I could gut an old windows ME HP machine I have in storage, but I doubt it is even strong enough to do the job. It was weak 6 years ago and likely misses the mark by a hundred watts or so.

[jdc2000]

Post the make, model, and wattage of the current power supply.

[maxximilian]

Is there a free piece of software I could run that monitors such things as power supply....that would log a drop in current or something?

[maxximilian]

Post the make, model, and wattage of the current power supply.

300 watts....

Full specs here: http://h20000.www2.hp.com/bizsupport...reg_R1002_USEN

[SuperSparks]

You could try this for monitoring voltages:

HWMonitor

I doubt you'll have much success though, if the voltage becomes unstable enough to affect the Power_Good signal (which is what causes the reset), it is instantaneous, and the restart will initiate before any software can display a problem I think

[jdc2000]

No FREE voltage monitoring software at the level you would need. Does that PC actually have the dial-up modem card in it? If yes, and you are not using it, try removing that, since it can cause the same issues if it is going bad, even if it is not being used. Other than that, a 300 watt generic power supply would be miinimal for that system. A test replacement is the way to go, if you can find one.

[maxximilian]

Thanks for the help. I was fairly sure this was software because of the shutdown sequence running, but you folks have given me something more to look into.

I did have a plan to gut this machine and put everything in a new larger case with a larger power supply....so I could upgrade to a better (powered) video card. If I can't solve this issue....I might have to move that plan up.

Just as a side question.....what size PSU should I be looking to upgrade to. Will need to power the current system and also a new mid-range graphics card.

[SuperSparks]

You'll be hard pressed to buy anything under 450 Watts anyway, which should be fine. Or you may find that you can get a 500 to 550 Watt one for much the same price. There is no harm in going for one larger than you need.

[maxximilian]

OK....that's about what I was thinking.....500 watts.

[Train]

A about idling 500 would last longer than a loaded up 300 would. Run cooler too.
Plus as you noted, they do allow for upgrade of video and the like.