Computer PSU query

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Kevin
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From what I can work out, the PSU in my computer has failed - it comes on and restarts within about 6 seconds. I disconnected all components and the same thing happens so I assume it is the PSU.

Does this sound right? Given that it reboots when nothing is connected, am I right in thinking that it is the PSU which has failed?

Thanks :)
 
Could be anything from leaking capacitors on the mainboard to screwed operating system. Not necessarily the power supply.

First thing first how old is the machine and what make is it ?
 
Thanks for the reply.

Intel 6th Gen Quad Core I5 6600 3.3GHz
16GB (2x 8GB) DDR4 2133Mhz Dimm
Novatech Power Station Black V2 Modular 850 Watt PSU
Novatech Eclipse High Performance Mid Tower Case
GIGABYTE GA-Z170XP-SLI Intel Z170 (Socket 1151) Motherboard
Arctic Freezer i30 CPU Cooler

That's the main parts.

Even with all cables disconnected from the PSU it reboots...
 
It's just over 3 years old and worked perfectly until this evening...
 
Have you tried unplugging everything from the PSU and then powering up the PSU?
 
Yes, only the PSU connected to the motherboard.

Is there a way to start the PSU without a mobo connection to the power switch?
Have you tried unplugging everything from the PSU and then powering up the PSU?
 
with everything disconnected from the PSU when you switch it on does it stay on?
 
You can get an ATX PSU to power up without a mobo connection using a paper clip.
atxpsu-jumper-300x224.jpg
Pins 14 & 15 on the 20-pin connector, 16 & 17 on the 24-pin.
They'll generally be coloured green and black.
 
Just a thought, is it overheating due to dust within the computer, so cuts out. if the cooling fans are not running properly!!!! I have had that problem in the past. Not just the case fans but the CPU cooling fan and any others (rocket blower helps)
Going into the Bios will tell what temp it is running at (hold down delete button while computer starts up)
 
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Forget all this thing loads off the PSU it proves nothing.

First thing to do is check the mainboard, look for little round tins about 4 or 5mm in diameter. They will have a mercedes badge style marking in the top. Check to see if there are any of them that look bulging or have brownish goo coming out of the top. The ones around the CPU are the most likely t go.
Let us know if there are any.

As psu will either work or not, it won't cause reboots.

( 30yrs IT Engineer )
 
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Good thinking... It is a little dusty. I'll try that now.
Just a thought, is it overheating due to dust within the computer, so cuts out. if the cooling fans are not running properly!!!! I have had that problem in the past. Not just the case fans but the CPU cooling fan and any others
 
Thanks, I'll check that out too.
Forget all this thing loads off the PSU it proves nothing.

First thing to do is check the mainboard, look for little round tins about 4 or 5mm in diameter. They will have a mercedes badge style marking in the top. Check to see if there are any of them that look bulging or have brownish goo coming out of the top. The ones around the CPU are the most likely t go.
Let us know if there are any.

As psi will either work or not, it won't cause reboots.
 
As psu will either work or not, it won't cause reboots.

( 30yrs IT Engineer )
And you're saying a fault can't happen? I learned the folly of that very quickly.
I've seen this once before; turned out the cheap PSU hadn't had one of the regulator heat sink bolts tightened, and the VR was looking a little blistered.
 
Not saying it never happens but it's very unlikely. I have been in the computer industry since 1979, in the field as a PC engineer for most of that. I personally have never seen a PSU cause rebooting this way.

I have seen however thousands of PC's with this problem that have either been screwed up operating systems or blown capacitors on the mainboard.

Kevin says his PC is from Novatech, I have used them many times and their kit is usually pretty damn good.

I'm always happy to bow to others greater intelligence though :D:D:D:D:D
 
Not saying it never happens but it's very unlikely. I have been in the computer industry since 1979, in the field as a PC engineer for most of that. I personally have never seen a PSU cause rebooting this way.

I have seen however thousands of PC's with this problem that have either been screwed up operating systems or blown capacitors on the mainboard.

Kevin says his PC is from Novatech, I have used them many times and their kit is usually pretty damn good.

I'm always happy to bow to others greater intelligence though :D:D:D:D:D

I can say that I have had exactly this. Faulty psu caused the exact same symptoms. PSU replaced, fault disappeared.
 
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Not claiming greater intelligence, just unlucky enough to have been presented with a variety of odd faults that couldn't/shouldn't happen, but did.
Ever seen a mobo that's afraid of the dark? We never did figure out that one.
 
Not claiming greater intelligence, just unlucky enough to have been presented with a variety of odd faults that couldn't/shouldn't happen, but did.
Ever seen a mobo that's afraid of the dark? We never did figure out that one.


Lol did it have case intrusion detection ?
 
Nope.
Basic mini tower case with two side panels. Mobo mounted on right looking from the front.
With the side panels on, it wouldn't boot. With the left panel off, it worked fine... until you put the panel back (no matter how carefully) and it would hang.
Take the panel off and reset; working fine again.
We moved the board to a different model case, and the same thing happened.
This was back before gaming cases were a thing; I wonder if it would've worked with a side window, or a light on in there...
 
It was an AT format socket 7 P1; back then, cases were beige boxes, and lighting rigs unknown. :(
 
Any chance it is the overheat "fuse" kicking in, the one under the CPU, because the heat sink/fan has become displaced??? NB I am surmising that the fan is running and that the heatsink itself is free of dust and crud!
 
Not claiming greater intelligence, just unlucky enough to have been presented with a variety of odd faults that couldn't/shouldn't happen, but did.
Ever seen a mobo that's afraid of the dark? We never did figure out that one.
I was once in charge of a group of PCs that had been upgraded from Intel to AMD processors (back when this was possible, around 1998). They were all running happily until one froze during POST. I took the lid off, couldn't see anything wrong so put the lid back on and tried it again - it worked perfectly. After that, if any of them froze during POST, the cure was to remove and replace the lid. And it was a permanent cure, never re-occurred on any of them.

I'm in the 'replace PSU' corner on this. It may not be the problem but it's an easy possible cause to eliminate. An 850W PSU is hugely over-specced for the rest of the OP's PC so possibly not running at a high enough load to work well.
 
I had a Computer that suddenly turned Off, sometimes after a few minutes on sometimes after a while,and the immediately turned back on again

Like you tried and checked every thing, one day my wife, Technophobe, said have you tried a new Mains Lead, Kettle Type, Silly woman but in desperation tried it and had no further trouble.

Just saying it might be that simple.
 
Using the paperclip, I find that the PSU stays running so I'm assuming it is not this.

With only the motherboard connected to the PSU, it restarts after about 8 seconds - the fan on the artic cooler runs so I presume this is ok.

There are no dirty / oozing capacitors on the mobo...

Any ideas before I decide to go back to Novatech for a new bundle?

https://www.novatech.co.uk/barebonebundles/view/bb-840016.html

This is what I'm thinking of.
 
Asking a daft question?

What you say infers that nothing has changed at all up untill the point of failure.

But had you physically moved very recently?
Apart checking it by disconnecting cables have you recently had it open for any other purpose?

Apart from my question re:is the HSF still firmly seated on the CPU are the front panel connectors all still in place and seated i.e. the start switch & the restart switch respectively?

Is it in the same orientation as previously (still upright Vs laying on its side or vice versa)?

Oh, are the sticks of RAM seated OK? FWIW at one time I had an issue (not the same as yours) and worked out by elimination & swap testing that one pair of my 4 RAM sticks were intermittently faulty......once I removed the pair it ran fine.
 
Ok- I'll try to explain step by step.

Jan 2016 I bought this as a bare bones system

I added 240gb ssd, 2 x 1tb sata drives, graphics card, 2 x DVD rw drives, pci 4 port usb.

I installed Windows 7, eventually upgraded to Windows 10.

It sat on my desk working perfectly until spring 2017 when we moved house. It returned to its place on my desk and worked perfectly.

Yesterday evening I turned it on, before the BIOS POST screen came on, it restarted.

I powered off and opened the side panel.

Powered on again, saw the mobo light up, then it restarted (mobo lights off, PSU restarts).

I disconnected hard drives, optical drives, removed graphics card and PCI vard and tried again. Same result.

Following advice above on how to test PSU, I connected the paperclip and found that the PSU runs ok without cutting out.

I removed both sticks of 16gb DDR 4 ram. Same issue.

I unscrewed the artic cooler and checked that it was properly seated. Same problem.

Unless anyone has a magic answer, I'm going to get a new barebones bundle from Novatech, although maybe not the one above - probably one with an upgraded mobo.

Thanks for all the suggestions.
 
You could pick up a Celeron G3900 for £35 on the bay. If you test with that and the fault disappears, your i5 is duff, if it doesn't, then it's likely the mobo.
If that's the case, any socket 1151 Skylake or Kaby Lake chipset board should slot in to your existing case* and take all your existing bits.
If the CPU's sick, and your mobo has the F20 BIOS version, you could potentially upgrade to a seventh gen i7-7700.

*Check the location of all mobo case mounting posts before fitting a new board, an unused post located where the new board doesn't have a hole can short it out.
 
I'd be tempted to clean and replace the cpu heat sink compound to ensure good thermal conductivity. It sounds like the psu is being switched off to protect the cpu overheating.
Any beeps at post by any chance?
 
I'd be tempted to clean and replace the cpu heat sink compound to ensure good thermal conductivity. It sounds like the psu is being switched off to protect the cpu overheating.
Any beeps at post by any chance?

Was thinking this also.
 
I think I found your problem ;
Ok- I'll try to explain step by step.

Jan 2016 I bought this as a bare bones system

I added 240gb ssd, 2 x 1tb sata drives, graphics card, 2 x DVD rw drives, pci 4 port usb.

I installed Windows 7, eventually upgraded to Windows 10.
.
Sorry. I'll get me coat.
 
The only thing I can think of beyond what's already been mentioned is that you haven't said anything about the 12V connection from the PSU to the MB. A bad connection there could cause repeated restarts, I think.
 
You could run an OS (Linux etc) from a USB stick to rule out Win 10 or not?
 
I've tried it with an alternative cable to no effect.
The only thing I can think of beyond what's already been mentioned is that you haven't said anything about the 12V connection from the PSU to the MB. A bad connection there could cause repeated restarts, I think.
 
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