Computer won't turn on till I unplug and replug from PSU

[Thriliya]

I've gone through the sticky and old post. But my problem is slightly different. There's no sudden shut down or any of sorts. I would use the computer and shut down normally. Then when I'll try to turn it on the next day it won't turn on. So I'll have to unplug the power cord from the PSU and replug it or I might just turn off/on the PSU switch. And then try to power on the computer would turn on. I'll use it without any kind of problem for the day and after shutting down without issues same happens the next day (no power till replug). It's been happening for 5/6 times now. My build is nearly 2 years old.

The PSU is Antec VP500(/550?)P and
The Motherboard is Gigabyte B450M DS3H

Any Help is Highly Appreciated

 

[Athlonite]

sounds like a misbehaving protection in the PSU best bet try another PSU from another brand if it still happens it means something in your PC is causing a protection trip to happen at shut down.

but best guess a new PSU should fix the problem and go with a better brand like seasonic or corsair

 

[looniam]

its old and wants to be given its gold watch.

hard latching, where you need to switch/unplug to reset, seems there is a protection giving a false positive when you shut down.

pretty sure its waaaay past that 3 year warranty?

 

[Thriliya]

hard latching, where you need to switch/unplug to reset, seems there is a protection giving a false positive when you shut down.

Even restarting works without issues.

pretty sure its waaaay past that 3 year warranty?

Nope, At best 1 year 9 months. Can't be more for sure

 

[Zyll Goliat]

Maybe your motherboard somewhere touching case and making contact from the backside...so your PSU refuse to turn on PC because of the protection mode....put some cardboard in between and see if that helps.....

 

[looniam]

Even restarting works without issues.

Nope, At best 1 year 9 months. Can't be more for sure

ah. you did say it was 2y/o but i looked when it was released, my bad.

i know it is not a sudden shut down problem but w/o another psu to check, you might need to breadboard everything and start from there. i had some mysterious stuff going on and found out my habit of keeping spare stand off/storage screws in the corner of my case wasn't too bright.

just saying - happy hunting(?)

 

[eidairaman1]

Maybe your motherboard somewhere touching case and making contact from the backside...so your PSU refuse to turn on PC because of the protection mode....put some cardboard in between and see if that helps.....

Just pull the motherboard and bare necessities to boot it.

 

[DoLlyBirD]

Fyi those psu's have been around for 10 years and they released a V2 under the same model name with worse specs than the original, likely cheaped out on some of the internals also, I'd suggest you get something a little more reliable and more recent

 

[Thriliya]

Just pull the motherboard and bare necessities to boot it.

Just tried to power on within 20 minutes after shutting down (without re-plugging). And yk what? It works! I think further troubleshooting is needed like most of you suggested.

 

[silentbogo]

There are few things you can check (both may happen when PC is in standby for awhile):
1) Disable "fast startup" under power settings. It's not the same as fastboot, and not the same as hybrid sleep, but may cause issues just the same
2) Electrical issues on +5VSB rail. May be caused by the motherboard or the PSU, but in your case I lean towards the latter (voltage instability causes CMOS to get confused until you power-cycle the system).

 

[Cryptomaniac]

I've gone through the sticky and old post. But my problem is slightly different. There's no sudden shut down or any of sorts. I would use the computer and shut down normally. Then when I'll try to turn it on the next day it won't turn on. So I'll have to unplug the power cord from the PSU and replug it or I might just turn off/on the PSU switch. And then try to power on the computer would turn on. I'll use it without any kind of problem for the day and after shutting down without issues same happens the next day (no power till replug). It's been happening for 5/6 times now. My build is nearly 2 years old.

The PSU is Antec VP500(/550?)P and
The Motherboard is Gigabyte B450M DS3H

Any Help is Highly Appreciated

Hi, did you ever find a solution to your problem? I have a similar problem with my Lenovo 700-25ISH and can't seem to find any solution.
Would appreciate an early reply. Thanks!

 

[Innes_UK]

I had this issue and it turned out to be the display port cable! With it plugged in, I could shut down the computer fine but it wouldn’t fire up when power button pressed. I had to switch off the psu and back on again and then it would work! I thought it might be the cmos battery so had the take out graphics card to get to it. I didn’t put it back on for testing so used the onboard DP graphics. Powered off and started with no problems. I put the graphics card in and plugged in both monitors. Tested it again and the problem came back! I then unplugged 1 monitor and it worked fine. Then tried the other monitor and problem came back. At this point I didn’t know if it was the monitor or the cable causing an issue so I swapped cables and turns out the cable was the cause. Ordered a new cable and all was fine. I had recently moved my computer further away from the monitors so the cable that was causing the issue was new but I’m wonderibg if the 1.4 do cable wasn’t happy with the 1.1dp monitor. Either way, try unplugging graphics card and use on board graphics with a different cable.

 

[evernessince]

I had this issue and it turned out to be the display port cable! With it plugged in, I could shut down the computer fine but it wouldn’t fire up when power button pressed. I had to switch off the psu and back on again and then it would work! I thought it might be the cmos battery so had the take out graphics card to get to it. I didn’t put it back on for testing so used the onboard DP graphics. Powered off and started with no problems. I put the graphics card in and plugged in both monitors. Tested it again and the problem came back! I then unplugged 1 monitor and it worked fine. Then tried the other monitor and problem came back. At this point I didn’t know if it was the monitor or the cable causing an issue so I swapped cables and turns out the cable was the cause. Ordered a new cable and all was fine. I had recently moved my computer further away from the monitors so the cable that was causing the issue was new but I’m wonderibg if the 1.4 do cable wasn’t happy with the 1.1dp monitor. Either way, try unplugging graphics card and use on board graphics with a different cable.

Could also be a DisplayPort Pin 20 issue, which can appear with DP cables that are wired incorrectly on video cards older than the Nvidia 20xx series.