Any expert PC builders out there?

Posted by: Hmack on 21 October 2016

I am aware that there are quite a few people on this forum with pretty impressive knowledge about PCs and PC Systems, so I hope that someone might be able to give me a few suggestions about a strange problem I need to resolve.

I have built my own PCs for many years, and also occasionally build computers for members of my family. The problem I need to resolve relates to a fairly high end PC I built for my Brother a year or so ago. I built this PC using a Fractal Design case, a modular Corsair power supply, Intel Core i7 processor with (I think) 8 Gb RAM. The operating system was originally Windows 7 (64 bit), which has fairly recently been upgraded to Windows 10 (64 bit), and is installed on a Corsair SSD.

This PC worked flawlessly for around 9 months, and then out of the blue developed a very strange (at least to me) problem that has persisted ever since, and I am struggling to work out exactly where the problem might lie. Unfortunately, although I build PCs, I don’t have access to any specialist diagnostic equipment and so I am at a loss as to how to approach the problem.

The problem manifests itself on ‘power up’, and is very consistent.

Once the PC has successfully booted up, it always runs flawlessly up until it is switched off, even if it left powered up for days on end. My brother has never encountered any problems when the PC is running.

The PC can be ‘restarted’ (for example when installing a new application, or upgrading from Windows 7 to Windows 10), and always boots up perfectly when restarted.

However, if the PC is switched off, it cannot be powered up again. It does not even appear to ‘post’, but just sits there doing nothing. I haven’t got around to buying a ‘post card’, so do not have any diagnostic information. A similar PC I built for myself uses a motherboard with a built in ‘post display’, but unfortunately the one I built for my brother does not.

Once switched off, the PC will not power up again until it is left powered down overnight (approximately 7 or 8 hours). After the PC has been left powered down for this duration, it will almost always power up successfully, and then for the duration of the time it is powered up, it will, as always, perform perfectly until it is switched on again.

I have run diagnostic checks on the RAM modules and tried exchanging these, but to no effect. The RAM modules appear to be absolutely fine.

Has anyone encountered a similar problem, or does anyone have any idea of what the problem might be? Power supply? Capacitor issues on the motherboard itself? I just cannot think of anything that could cause the persistent and consistent problems he is experiencing. I suspect I will have to end up taking the PC to a competent and trustworthy repair shop (if I can find one), but in the meantime, can anyone provide any suggestions as to what might cause this problem.  

Incidentally, the problem first manifested itself whilst the PC was running Windows 7, and continues identically following the upgrade to Windows 10.   

Posted on: 21 October 2016 by Bananahead

My guess is video. If you have a different video card then try that.

Are you certain that the system is being shutdown and not put into sleep or hibernate? (my current system won't wake up - well it does but not the video system)

Have you cleaned it? Opened the case and blown the dust out.

Posted on: 21 October 2016 by Hmack

Bananahead, thanks for the reply.

Actually, I did try replacing the video card, since I had a spare one available.  Sorry, I should have mentioned this in my original post.

I did of course remove the case when I tried the different video card, and also checked that the case power & reset functions were connected to the motherboard correctly. The inside of the case was still virtually spotless. Absolutely no dust or grime present at all.

I am also pretty sure that the system is shutting down and not going into hibernation. Switching off the power supply & disconnecting the power lead following a shutdown also does not appear to have any impact on the recovery time.

Posted on: 21 October 2016 by Bananahead

It does sound like a power retention challenge.

Faulty power supply? Do you have a spare?

Posted on: 21 October 2016 by Hmack

Actually, I do have a spare power supply. Unfortunately, it isn't a modular power supply, so not as straightforward as it might have been to simply swap the unit and leave the power cables in place.

I may be tempted to just buy another modular supply to give this a go. Although the power supply is normally one of the first things I would check out for many problems, I find it difficult to link the specific problem  with this PC to a faulty power supply. However, I have come across a few problems in the past which I couldn't logically understand, and which turned out to power supply problems, so it's worth a go.

Can you describe to me what you mean by a 'power retention challenge'? It sounds very plausible, but what exactly is it

Posted on: 21 October 2016 by fatcat

I’m no expert but I had a similar problem with a laptop a few years ago. The fix was, remove the battery, press start for about 10 seconds, this drained the residual power from the capacitor. Once battery inserted the laptop started OK.

I think the problem was caused by the fact, it didn’t actually shut down, it only appeared to shut down

 

I built a PC about nine months ago, it’s running W10 64 pro on a motherboard designed to run W10. It can be powered up, from shutdown without even pressing the start button on the PC. Simply left clicking the mouse starts it up.

 Have you tried putting it to sleep instead of power off during the day.

 I’ve encountered startup problems in the past caused by HD conflicts. Might be worth removing all but the drive containing the operating system to see if that’s the problem.

Posted on: 21 October 2016 by Jan-Erik Nordoen

It sounds very much like a power supply issue.

FWIW, my music PC  - a UnitiServe HDD - displays exactly the same behaviour with its external custom-built power supply. I have to leave the US and the power supply switched off for at least an hour before I am able to restart it. When the power supply builder was trying different prototypes, he found that the US briefly drew high current levels (up to 10 amps) when starting up. Unless the power supply is cold, it cannot provide enough 'juice' for start-up.

Possibly a similar issue with your PC? Maybe worth trying a higher current capacity power supply to see if that fixes the issue.

Jan

Posted on: 31 October 2016 by Hmack

Thanks everyone.

You persuaded me to take the risk and purchase and fit a new (and slightly higher wattage) power supply to my brother's PC, and this has completely cured the boot-up problem.

Still doesn't appear to be completely logical to me, but faulty power supplies appear to be capable of causing some very weird and wonderful issues.

Posted on: 31 October 2016 by Bananahead
Hmack posted:

Thanks everyone.

You persuaded me to take the risk and purchase and fit a new (and slightly higher wattage) power supply to my brother's PC, and this has completely cured the boot-up problem.

Still doesn't appear to be completely logical to me, but faulty power supplies appear to be capable of causing some very weird and wonderful issues.

This is the Naim forum. Lot's of advice about power supplies and their importance here.