Computer Dying Randomly [Seems it was the PSU]

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Jorpho
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Computer Dying Randomly [Seems it was the PSU]

Postby Jorpho » Mon Oct 09, 2017 2:22 am UTC

I fear I might be in the market for a new PC again.

My PC has started to exhibit an alarming tendency to completely power down without warning. The only consistent thing I've noticed so far is that the shutdown only occurs when I'm sitting at the PC doing stuff. (In fact, the last couple of times it has been right after moving the mouse cursor.) I have made no changes to the internal hardware, and nothing in particular has changed externally either – I have a new pair of headphones, I'm using a different USB cable with one of my joypads, that sort of thing.

Of particular note is that once the PC shuts down, it will only power back up again after I leave it unplugged for about thirty seconds. What could this mean? Nothing else plugged into the same outlet seems to be affected. (I have currently unplugged anything else on the same outlet to be sure.)

Should I buy a surge protector? (Maybe it's related to the fact that I'm using my heater again these days..?) Is it time for a new PSU?

Last time I started seeing something like this I wound up getting a new motherboard, but as I said, the PC seems to be powering on just fine and operates quite merrily until it suddenly doesn't.
Last edited by Jorpho on Tue Oct 10, 2017 4:14 pm UTC, edited 1 time in total.

Tub
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Re: Computer Dying Randomly

Postby Tub » Mon Oct 09, 2017 10:00 am UTC

Might be the PSU, might be overheating, might be a damaged motherboard, might even be a faulty USB device. If you mention crashes when moving the mouse, then check the mouse first.

Do you have a spare mouse and keyboard? If so, unplug *all* USB devices, plug in the spares, see if the problems persist.
Can you monitor CPU and GPU temperature? Have you checked all the fans (including PSU fan) to see if they're spinning?
Did you do a memtest? (unlikely to be the problem, but cannot hurt)
Do the crashes appear more often when the machine is under load, e.g. when gaming?

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HES
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Re: Computer Dying Randomly

Postby HES » Mon Oct 09, 2017 10:00 am UTC

Jorpho wrote:completely power down without warning

only occurs when I'm sitting at the PC doing stuff

it will only power back up again after I leave it unplugged for about thirty seconds

I'm no expert, but sounds a lot like it's overheating. Most systems will shut down at a threshold to protect the hardware. Might be worth checking temperatures with something like CoreTemp.

Then it may be the case that just a fan clean will solve your worries, rather than having to replace anything. Always good to check the simple stuff first.
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Soupspoon
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Re: Computer Dying Randomly

Postby Soupspoon » Mon Oct 09, 2017 10:27 am UTC

It could be so many things, as already mentioned, but the last machine of my own that suffered such a problem did so because of a blown capacitor (not non-working, but sent out of tolerance) presumably involved in part of the internal mobo power regulation function. Perhaps it was manufactured flaw that made it the first to fail, but it was also one of the closest to the CPU heatsync, so always going to have that little more heat on it than other similar caps slightly further away from there.

On the off-chance that it is that...
Spoiler:
The good news is that if you find such a cap (look at the expose metal tops, especially of the ones nearest any heatsynced components, and one may obviously 'bulge', even if not miscoloured with some expelled dialectric) you can replace it.

The bad news is that often the easily obtained equivalent microfarad/whatever rating of capacitor may be bulkier than the mobo-manufacturer used (Dell seems to use an effectively unavailable mini version, which I always think is more susceptible to going over-tolerance and failing, the number of times I've seen this, and I've never found a direct replacement that isn't twice the size, sometimes needing creative solutions to fit back in to the space.

And, of course, this means taking a soldering iron to the mobo, which is very much the stage at which you're probably going to just want to say "fuggit" and go for a new computer (or, at the very least, mobo, and then 'necessary' upgrades to RAM, CPU, etc) rather than getting either yourself or your Friendly Neighbourhood Solderman to dive in there and actually do the scary replacement.

...but I couldn't say that it's that for sure without an actual eyes-on check. And maybe it'd still be better to use this "occasionally fails" problem to get in there and make sure that all data, configuarations, settings, etc are backed up or recorded at the same time as going looking for a new machine to migrate them to (or recreate, where there's no easy straight-migration option).

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Xenomortis
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Re: Computer Dying Randomly

Postby Xenomortis » Mon Oct 09, 2017 11:36 am UTC

Over heating is the obvious one - check all the fans for dust, etc, particularly for the PSU and CPU.

It could be the power supply - if it's old and your computer already pushes close to its rated limit then it may no longer be able to provide enough juice.

Jorpho wrote:Of particular note is that once the PC shuts down, it will only power back up again after I leave it unplugged for about thirty seconds. What could this mean? Nothing else plugged into the same outlet seems to be affected. (I have currently unplugged anything else on the same outlet to be sure.)

Unplug it and try to turn it on (PC's will often give a quick blink of life when you do this, as the capacitors still have some charge) - see if that removes the 30 second wait you have to endure, that might suggest a problem with a capacitor (you look over the motherboard for one that looks blown). If you get to the "soldering iron to PC component" stage, it's also best to have a backup plan (usually a spare component or alternative computer).
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Jorpho
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Re: Computer Dying Randomly

Postby Jorpho » Mon Oct 09, 2017 6:24 pm UTC

Overheating, eh? That would be consistent with my observation that the fans don't seem to be making nearly as much noise as they used to. I've never been quite sure as to what exactly is the noisiest fan in the system, but I reckon the PSU would be the biggest.

I haven't been gaming much lately (except for AM2R, which is hardly demanding). I tried firing up Post Apocalyptic Mayhem just now (which previously provided some interesting experiences) and I couldn't get through the menus before the computer died again. I had HWInfo running at the same time on another monitor but could not observe any exciting temperature spikes - but then, HWInfo doesn't seem to monitor the PSU temperature.

I tried swapping out the keyboard and my USB hub, but that did not stop the dying.

I suppose I'll go looking for a new PSU tomorrow, and while I've got the system open I'll have a chance to check for any signs of obvious physical damage. I'm typing this up on one of my spare PCs, but it is a painfully outdated clunker that I have long been meaning to swap out for a spiffy P4 at 3.2 GHz.

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Re: Computer Dying Randomly

Postby Tub » Mon Oct 09, 2017 9:19 pm UTC

Jorpho wrote:Overheating, eh? That would be consistent with my observation that the fans don't seem to be making nearly as much noise as they used to. I've never been quite sure as to what exactly is the noisiest fan in the system, but I reckon the PSU would be the biggest.

Bigger fans are usually quiter. They need less RPM for the same airflow. But like I said, go visually check if all the fans are spinning when the system is running!

Your BIOS will probably have some diagnostics page telling about the relevant system voltages. Are those looking good?

If you've bought a complete system and/or a cheap PSU included with the chassis, it's quite possible that the PSU is the problem. If you bought a reasonably oversized PSU from a reputable brand, it should survive 5+ years without issues.

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Jorpho
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Re: Computer Dying Randomly

Postby Jorpho » Tue Oct 10, 2017 1:26 am UTC

Tub wrote:Bigger fans are usually quiter. They need less RPM for the same airflow. But like I said, go visually check if all the fans are spinning when the system is running!
Well, does the PSU fan often spin up loudly when the system goes under load? Or do PSU fans usually run at constant speed? Because when I say the fans are a lot quieter than usual, I mean in particular that I'm not hearing any of them spinning up like they usually do.

I'll take a closer look at the fans later, but I would have thought the system wouldn't be stable at all if one of the fans was completely dead.

Your BIOS will probably have some diagnostics page telling about the relevant system voltages. Are those looking good?
I can see those in HWInfo too. None of them look ... bad, I guess?

If you've bought a complete system and/or a cheap PSU included with the chassis, it's quite possible that the PSU is the problem. If you bought a reasonably oversized PSU from a reputable brand, it should survive 5+ years without issues.
It's a Thermaltake, purchased separately some time ago.

ETA: Confirmed visually: case fan, CPU fan, PSU fan, and GPU fan are all spinning merrily with the case open. There wasn't even very much dust, and there are no capacitors blown on the motherboard. PAM didn't even make it to the menu this time, though.

The only thing slightly worrying is that some of the unused PCI slots below the GPU are really grimy.

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Jorpho
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Re: Computer Dying Randomly

Postby Jorpho » Tue Oct 10, 2017 4:13 pm UTC

Okay, new power supply is installed and PAM (which I doubt has ever found such utility as a benchmark) now starts up flawlessly. So far so good. The case is now howling oddly again, for whatever reason.

I'm glad I didn't start with a surge protector. That was probably just wishful thinking on my part.

I guess the next step is to make a warranty claim with Thermaltake. (The PSU is two years into its five-year warranty period.)

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Re: Computer Dying Randomly [Seems it was the PSU]

Postby ericgrau » Sat Oct 21, 2017 3:40 pm UTC

Of note I had a similar issue on a computer I had for several years and warrantied a few PSUs. I wondered why so many PSUs were so unreliable. Eventually lost a video card too and wondered if that was the cause. Researched a bit further and turns out the motherboard was eating PSUs by causing power surges with faulty capacitors. Maybe it fried the video card too. If it happens again or anything else fails I'd look at the mobo. I mean hardware is pretty reliable. So if hardware fails on you twice within a couple years you're either really unlucky or it's actually the same component again that destroyed one of your others.

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Jorpho
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Re: Computer Dying Randomly [Seems it was the PSU]

Postby Jorpho » Mon Oct 23, 2017 6:28 pm UTC

ericgrau wrote:Researched a bit further and turns out the motherboard was eating PSUs by causing power surges with faulty capacitors. Maybe it fried the video card too. If it happens again or anything else fails I'd look at the mobo. I mean hardware is pretty reliable. So if hardware fails on you twice within a couple years you're either really unlucky or it's actually the same component again that destroyed one of your others.
I wondered if something like that was possible. Usually you would expect things to happen the other way around, i.e. faulty capacitors in a PSU frying motherboard after motherboard. But then, motherboard oddities might explain the very mysterious clock problem which still shows up intermittently for no apparent reason.

I should add that this is a Dell Vostro and one might expect their components to be vaguely reliable (as opposed to, say, PCChips).

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Re: Computer Dying Randomly

Postby Soupspoon » Mon Oct 23, 2017 7:00 pm UTC

Regarding Dell:

Soupspoon wrote:…<within the spoiler>The bad news is that often the easily obtained equivalent microfarad/whatever rating of capacitor may be bulkier than the mobo-manufacturer used (Dell seems to use an effectively unavailable mini version, which I always think is more susceptible to going over-tolerance and failing, the number of times I've seen this, and I've never found a direct replacement that isn't twice the size, sometimes needing creative solutions to fit back in to the space.
Unclosed parenthesis aside, it is the case that I've had (I think) two failed mobos that were not Dell (and the first of these took a Slot 1 processor, to give you an idea of the timescale involved) and personally replaced Dell mobo caps on a half-dozen/dozenish boards (in different places of work) when given the go-ahead to give it a go to not waste not-yet-obsolete hardware that we didn't need to. (It's all too easy to just junk things and replace, I know, but it seemed worthwhile at the time.)

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Re: Computer Dying Randomly [Seems it was the PSU]

Postby ericgrau » Tue Oct 24, 2017 4:58 am UTC

Jorpho wrote:
ericgrau wrote:Researched a bit further and turns out the motherboard was eating PSUs by causing power surges with faulty capacitors. Maybe it fried the video card too. If it happens again or anything else fails I'd look at the mobo. I mean hardware is pretty reliable. So if hardware fails on you twice within a couple years you're either really unlucky or it's actually the same component again that destroyed one of your others.
I wondered if something like that was possible. Usually you would expect things to happen the other way around, i.e. faulty capacitors in a PSU frying motherboard after motherboard. But then, motherboard oddities might explain the very mysterious clock problem which still shows up intermittently for no apparent reason.

I should add that this is a Dell Vostro and one might expect their components to be vaguely reliable (as opposed to, say, PCChips).

The PSU has fewer bigger caps which need less precision, while the mobo has more smallercaps which need more precision. But I mean, IF it fails again then look at the mobo. If not, then it probably was the PSU after all.


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