Odd computer problem

tberry6686

Bit of an oddball problem with my computer and I've run out of ideas.

Computer runs fine but when under heavy load often switches off with no warning. Then it will do nothing for about 5 minutes (won't switch on). After about 5 minutes it re-starts and I can log back in with no issues. I suspected it may be overheating so replaced the cpu cooling with a liquid cooler - at sustained max load cpu doesn't get above 40 deg now.

I cleaned the case fans (and replaced 1 that seemed iffy) when I replaced the cpu cooling.

Any suggestions. (I've checked all cables and they are connected ok).

Fightsback

tberry6686 wrote: »

Bit of an oddball problem with my computer and I've run out of ideas.

Computer runs fine but when under heavy load often switches off with no warning. Then it will do nothing for about 5 minutes (won't switch on). After about 5 minutes it re-starts and I can log back in with no issues. I suspected it may be overheating so replaced the cpu cooling with a liquid cooler - at sustained max load cpu doesn't get above 40 deg now.

I cleaned the case fans (and replaced 1 that seemed iffy) when I replaced the cpu cooling.

Any suggestions. (I've checked all cables and they are connected ok).

Could be a power supply unit issue, the voltage may becoming unstable or overheating at high current. New PSU in that case.

edit:
You may be very close to the PSUs wattage rating if you have any extras in there such as more HDDs and a powerful discrete graphics card, some graphics cards need quite a bit of current, in which case upgrade the PSU.

victor2

PSU would be where I'd look next too.

bod1467

Also remove, wipe and reseat your RAM sticks.

Fightsback

bod1467 wrote: »

Also remove, wipe and reseat your RAM sticks.

nah looks like the PSU is thermal tripping.

PS do not wipe the ram sticks - you could blow them with static electricity !

System

tberry6686 wrote: »

Bit of an oddball problem with my computer and I've run out of ideas.

Computer runs fine but when under heavy load often switches off with no warning. Then it will do nothing for about 5 minutes (won't switch on). After about 5 minutes it re-starts and I can log back in with no issues. I suspected it may be overheating so replaced the cpu cooling with a liquid cooler - at sustained max load cpu doesn't get above 40 deg now.

I cleaned the case fans (and replaced 1 that seemed iffy) when I replaced the cpu cooling.

Any suggestions. (I've checked all cables and they are connected ok).

Hi

On the motherboard are large capacitors usually close to the CPU, and these are to provide a power boost when doing intensive work.

It is possible that you have a failed capacitor.

Fightsback

johndough wrote: »

Hi

On the motherboard are large capacitors usually close to the CPU, and these are to provide a power boost when doing intensive work.

It is possible that you have a failed capacitor.

Unlikely as his computer won't turn on for five minutes so it looks like the thermal protection circuit of his PSU - easily diagnosed with a multimeter. It's a usually thermistor or sometimes relies on reverse breakdown of a diode.

tberry6686

Only thing that bothers me about it being the PSU cutting out due to temp is that I can be running the machine flat out for 8hrs and it's fine. Other times it runs for about 15mins and dies. I suspect some sort of intermittent fault and thinking more about it the prime suspect would have to be the PSU. Anyone recommend a good reliable PSU to run
AMD 6 core CPU, 16gb ram, graphics card (can't remember the type but is a couple of years old so not the most demanding), SSD, 2 normal HDD's, 2 Blu ray burners.

Fightsback

tberry6686 wrote: »

Only thing that bothers me about it being the PSU cutting out due to temp is that I can be running the machine flat out for 8hrs and it's fine. Other times it runs for about 15mins and dies. I suspect some sort of intermittent fault and thinking more about it the prime suspect would have to be the PSU. Anyone recommend a good reliable PSU to run
AMD 6 core CPU, 16gb ram, graphics card (can't remember the type but is a couple of years old so not the most demanding), SSD, 2 normal HDD's, 2 Blu ray burners.

Are you running anything from USB when it cuts out, that just might be enough to push it over. You need to see what type of PSU you have before you order a new one, modular or with built in cables. Also check the wattage rating of your current PSU.

Some of those amd 6 cores are 125w cpus, depending on the graphics card you have it could be pulling 300w alone if it's a really high end card. For that system I would put nothing less than a 600w PSU or higher depending on the GPU.

Get one by a reputable manufacturer such as coolmaster or corsair, not one of the cheap and nasty chinese OEM type.

If you have access to a voltmeter it would be worth checking the ATX plug voltages the next time it does trip to confirm it is the PSU before parting with cash.

tberry6686

Can't remember the make of PSU in the machine but it wasn't a cheap no name type (750w). I have ordered a 1000w corsair (probably overkill) so hopefully that will fix the issue.

Cisco001

tberry6686 wrote: »

Can't remember the make of PSU in the machine but it wasn't a cheap no name type (750w). I have ordered a 1000w corsair (probably overkill) so hopefully that will fix the issue.

I don't think you will need 1000W...
Even with one high end video card, you will be looking at 600W PSU...