PS Issue?

[racin510]

After no use for a couple of weeks I turn on my PC and it acts like normal boot up and then shuts down. Initially screen lit up, but after several shut downs I got nothing. Left it unpluged for a day and now when I turn on the PC on/off switch the PS seems to come on, and without pushing the power button. It runs steadily, doesn't shut down, but no boot up. Nothing on screen.
Does this sound like a Power Supply taking a dump?

 

[Cycloid Torus]

Depending on the details (did it POST?, were there 'beeps'?, fans all spin?, what did appear on screen?, etc), it could be that the PSU can no longer provide a 'power good' signal due to some issue in the PSU. Other candidates for issue are HDD is failing, Windows 10 has taken control for an update, corruption of boot record or critical drivers... and probably 6 other things I can't imagine at the moment.

I keep an extra power supply so I can swap a suspect one out. I turn off sleep & hibernate and let the machine sit while 'on' for hours and hours to allow Windows 'update' if there is any sign of HDD activity. I boot from flash USB media to see if HDD is kaput. I start in safe mode to see if drivers are messed up. I remove connection to power button and briefly connect "power on" to see if power switch is broken.

Others may offer better ideas. Better detail might narrow possibilities.

 

[racin510]

Hi and many thanks for sharing. Nothing comes up on screen now. The PS fan does fire up when the PS switch is turned on and all other fans run. Pushing the start button has no effect. This built for me PC never had a speaker hooked up so can't respond to beeps. Nothing comes up on screen. System is Win7.

Should I next try and measure PS voltage out put? If so is there any thing specific I should look for to determine if PS is bad?

 

[racin510]

OK I checked PS voltages and I get #9 [should be +5V] standby reading 11.56V.
1&2=3.5V
4&6=5.3V
10&11=12V
12=3.5V
13=3.48V
14=11.66V
21,22,23=5.3V

Is #9 the probable issue?

 

[Cycloid Torus]

+5v Standby should be 5v, but there is a chance that you got a false measurement.

You could take the 'exhaustive' route [ https://www.wikihow.com/Check-a-Power-Supply ], but it might be cheaper easier to just borrow or buy another PSU. No poking around inside the PSU unless you are a trained tech - capacitors hold enough power to take you out.

Your motherboard should have 2 pins for internal speaker - check manual - they cost about $1 each.