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Question

Have to flip PSU switch on and off to turn on PC

Sep 10, 2015 5:07AM PDT

Hi, I'm having an odd issue here and am hoping to find some help.
My PC is working fine, I reinstalled Windows two months ago. Yet around a month after I started having a strange issue with it. If I shut down the PC overnight and try to turn it on the next day, I have to flip the PSU switch off and on again for it to start. This doesn't happen if I shut down and then turn it on again in a shorter time, like an hour later.

I first initially fixed this problem by clearing the CMOS/updating the BIOS. I can't say for sure which one fixed it as I did both at the same time. Yet, around two weeks ago, the problem has returned. I noticed that after returning from a week holiday, that I had to flip the switch to turn on my PC when I returned (I had the PC unplugged from the socket during this time). In the last few days I have to flip the PSU switch to turn it on every morning after I've shut down for the night.

The PC works perfectly once it is on so I'm quite confused as to what's causing this. Is it possible that a fault in my house's electric circuit is causing this, as the house is quite old?. The PSU is less than a year old. Any help would be appreciated.

Specs:
Windows 7 64 bit
8GB DDR3 RAM
GTX 770
Corsair CX750W
120GB SSD and 3TB HDD
MSI G43/Z87 MOBO
i5 4570 3.20ghz

Discussion is locked

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Answer
This has been seen at the shop.
Sep 10, 2015 5:14AM PDT

But it may infuriate you that it's been either or both of the PSU and/or motherboard. The problem units did same at the client's home or the shop counter but so far we've had to nod a lot and swap the PSU on th bench first to know which it may be. To make our lives worse, once in a while it was both PSU and board.

-> Remember I take your work it's not a configuration issue as it worked when new.

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Further questions
Sep 10, 2015 10:04AM PDT

Ah, I hope it doesn't come to that. I was advised on another forum to replace the CMOS battery so I will try that first. Both the PSU and MOBO are both just over a year old so I will replace the CMOS and then report back here to see if that fixes it. If I may ask, do you think that the case power button could be broken? The case is 5 years old so I was wondering if it could be that.

And yes, I don't think it's a configuration issue as I didn't have this issue for a year or so after I built the PC initially.

Thanks for the help.

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That's a NEW CLUE.
Sep 10, 2015 10:25AM PDT

When folk recycle cases they sometimes leave in an extra post that slowly grinds through the paint on the motherboard and later, shorts or odd issues.

The CMOS battery is 30 cents in bulk but we don't change them. We whip out the Volt meter and if it's the usual CR2032 a reading over 3V is a pass. Under and we pop in a new one.

Remember that clues and stories helps. Now I suspect that old mounting post issue as well.

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Interesting
Sep 10, 2015 12:01PM PDT

Hmm, I didn't think of this. Would you mind explaining this issue in more detail to me? And how I can go about checking if this is it.

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Unsure how to expand on that.
Sep 10, 2015 12:11PM PDT

The post is under the motherboard where there is no corresponding hole. It works for a time until the vibration grinds through the paint. It can do nothing, fry the board or cause weird issues. Really annoys folk that want a solid answer but it's something you see too often.

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Makes sense now
Sep 10, 2015 1:49PM PDT

I see now, I didn't understand initially. I'll have a look tomorrow and post back here.

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remember that screw you lost...
Sep 10, 2015 12:15PM PDT

...putting in a new drive? You just found it. Wink

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New development
Sep 12, 2015 8:19AM PDT

Hi, I was wondering if you could help me with a new development.

The PC is now not powering on at all. It was working fine last night but this afternoon there is no sign of power. Does this help diagnose the issue? If seems PSU related now so I thought to try the paperclip test, as well as a new CMOS battery.

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When that happens to me
Sep 12, 2015 8:31AM PDT

I pull the motherboard out and place it on cardboard with the bare minimum parts. If that fails I swap what I suspect first.

I missed where you did that extra mounting post check.

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Seemingly fixed
Sep 13, 2015 8:31AM PDT

Hi, I thought I'd tell you that today I got the new CMOS battery and swapped it in and now the PC is booting. I'll have to monitor the situation but hopefully I've solved it.

Thanks for your help.

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Thanks for the update.
Sep 13, 2015 8:49AM PDT

I'd still want to be absolutely sure about mounting posts. We've seen thousands of PCs and other things over the decades (pre-DOS machines and shop) so while a new battery fixed this one, I've run into the battery draining due to that old mounting post issue more than once over the years.

You have some great advice in both forums but the post issue is one I always want to be sure of.

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I will take a look
Sep 14, 2015 4:47AM PDT

I'm planning to change cases soon so I will have a look and see then.

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Answer
check the power button on keyboard
Sep 10, 2015 12:01PM PDT

see if it's sticking. Check sleep button too.