Computer only starts when I hold down the power button:- Faulty Power Button or Faulty PSU?

Freddie1980 · 26 Jul 2019 at 14:12

Edit: Issue has been resolved. It turns out my PSU was faulty.
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I had this issue with my aging PC for ages, when I go to turn the computer on from cold most of the time the computer won't start when I press the power button. To get it to start I have to hold in the power button for about 5 to 10 seconds, release and then press it again and that generally after that it works (not always so I have to repeat the process) but it's annoying.

I had to replace the motherboard and video card sometime ago but I'm still having the same issues turning the whole system on. I tend to think it's either the PSU (Corsair AX650) or the actual power button on the case (Corsair 350D). Has anyone else had this issue or know what part it the likely culprit?

Plec · 26 Jul 2019 at 14:14

Have you replaced the cr2032 (CMOS) battery in the past couple of years (or ever)?

If not - i would swap in a new one - easy test.

Danny75 · 26 Jul 2019 at 14:31

Can also unplug the power/reset cables from the motherboard and use screwdriver tip on the two power pins to start it up a few times, see if it's any different. Though PSU is likely culprit.

Speaking of PSUs, had one explode yesterday in an old system I was messing with to see which parts were in good shape etc. A cheapo "700w". It sounded like a light bulb exploding.

Plec · 26 Jul 2019 at 15:04

Danny75 said:
Speaking of PSUs, had one explode yesterday in an old system I was messing with to see which parts were in good shape etc.

I hate working on old systems for exactly this reason - especially if it's a seemingly innocuous upgrade.

I'll spiel out all the necessary caveats about moving an old HDD/PSU/etc that's been comfortable in its position for the last 7 years may cause it to have a conniption fit and die. But, even after emphasising this, the look of disdain on their faces when said component drops dead makes you realise they were nodding in agreement to thin air... (I refuse to help my parent's friend's when i visit now - too confusing. I need a translator for their 'get to the ****ing point' and they need a translator even for my dumbed down version.)

Danny75 said:
It sounded like a light bulb exploding.

Scariest noise in the world - along with changing guitar strings and pulling them through the bridge *shudders* (you would think i would be immune to it by now) :/

Freddie1980 · 26 Jul 2019 at 15:14

I replaced the motherboard back in February and I'm sure I have some space CMOS batteries around somewhere. Thanks for the suggestion.

I must admit I did do some reading on this matter (all be it there wasn't much material coming up on google) and that also pointed towards the PSU. Shame that PSU cost a lot of money but there have been a few posts around here about Corsair PSU's not cutting the mustard in terms of reliability. I have an old Seasonic in my HPTC which is still going well, I might rip that out and try it and see that fixes the issue.

Greboth · 26 Jul 2019 at 15:36

Before you go through the effort of taking the PSU out I'd check the switch first. As Danny75 said above, disconnect the power switch from your motherboard and use a flat blade screwdriver to connect the 2 pins on the motherboard. The PC will turn on when you connect the 2 pins and should stay on even after you remove the screwdriver. If it does then it would suggest it isn't your PSU and could be your switch or alternatively, if it turns off then it is reasonably safe to assume your switch is fine and your PSU is the no.1 candidate.

Danny75 · 26 Jul 2019 at 15:52

Plec said:
I'll spiel out all the necessary caveats about moving an old HDD/PSU/etc that's been comfortable in its position for the last 7 years may cause it to have a conniption fit and die. But, even after emphasising this, the look of disdain on their faces when said component drops dead makes you realise they were nodding in agreement to thin air... (I refuse to help my parent's friend's when i visit now - too confusing. I need a translator for their 'get to the ****ing point' and they need a translator even for my dumbed down version.)

"Why are you warning me? Just get on with it and if the power supply dies let me blame you for killing it, when it had been fine all this time."

Plec · 26 Jul 2019 at 16:02

Danny75 said:
"Why are you warning me? Just get on with it and if the power supply dies let me blame you for killing it, when it had been fine all this time."

LOL - i'm glad i had my glasses on, i almost didn't see the speech marks.

Danny75 said:
Speaking of PSUs, had one explode yesterday in an old system I was messing with to see which parts were in good shape etc.

Did you suffer the look of poorly masked disdain? Or were they under the age of Gandalf's half brother and understood?

Danny75 · 26 Jul 2019 at 16:05

Plec said:
LOL - i'm glad i had my glasses on, i almost didn't see the speech marks.

lol

Plec said:
Did you suffer the look of poorly masked disdain? Or were they under the age of Gandalf's half brother and understood?

Decent guy, no problems. I'm just also familiar with the sort you were referring to.

PowerPie5000 · 26 Jul 2019 at 21:46

Try flicking the switch to the off position on the actual PSU (or unplug from wall) and leave it for about 20 minutes. Switch it back on (or plug it in) and see if the PC powers up first time when you press the power button on the case.

I had this issue with an old HP PC a while back and it turned out to be a faulty PSU (most likely bad caps).

Freddie1980 · 27 Jul 2019 at 07:56

PowerPie5000 said:
Try flicking the switch to the off position on the actual PSU (or unplug from wall) and leave it for about 20 minutes. Switch it back on (or plug it in) and see if the PC powers up first time when you press the power button on the case.

I had this issue with an old HP PC a while back and it turned out to be a faulty PSU (most likely bad caps).

Funnily enough when I rebuilt it with the new motherboard it did boot up first time of asking but after that it went back to normal.

Freddie1980 · 27 Aug 2019 at 09:59

Just to give some closure on this I swapped out the PSU (Corsair AX650) with my much older and uglier Seasonic (naked cables) and the issue has been fully resolved. I have to say though I'm really disappointed with that Corsair PSU, it wasn't cheap and I expected it to last a long time (my PC bear gets stressed this days, web browsing and light gaming in the form of AOE 2).