I powered off my computer before heading to work, but when I came home four hours later, it wouldn't turn back on. I have it plugged into a surge protector, which seemed fine because everything else was working. After doing some research, I suspected the power supply unit (PSU), so I replaced it, but the problem persists. When I toggle the PSU off and then back on, the fan light flashes, but nothing else indicates it's working—the power button doesn't respond either.
5 Answers
Go ahead and unplug everything from your PC to start. If the fans kick on and it sounds like it’s alive, then it might be something that was connected causing the issue. Try plugging in components one at a time and turn the PC on after each one to see if one of them is the culprit.
There’s a chance the new PSU is defective. If you have a multimeter, it might be worth checking the voltage output to make sure it’s delivering properly.
Just a heads-up: surge protectors can sometimes fail to protect against surges. Don’t assume that’s not the problem just because your setup seems fine.
Make sure it's not an issue with your monitor. Unplug and drain the capacitors by holding down the power button on it for a minute. You could also test it with another device to see if it’s working.
Have you tried unplugging the power cable and holding down the power button for at least 30 seconds? That sometimes resets things. If that doesn’t work, it could still be the PSU that’s faulty, even with the new one.
The surge protector I have shuts off if there's a power issue—my monitor was still on, so I doubt it was that.