Question computer won't turn on

[justAMK]

I built my PC in 2018. I’ve been using it without any problems since. I do my best to take care of my PC. I use compressed air to clean off the dust. I always shut off my PC every night.

small back history of my PC
There was a CMOS issue that I resolved by installing a new one that was more than a year ago, and sometimes there are some power outages, so I kept my PC in sleep mode for a couple of hours through my backup UPS, but then I stopped doing that. Recently my UPS battery is dead, so when the power goes off, so does my PC, but there are no issues when I restart my PC.

This morning, when I tried to turn it on, nothing would respond. The LED lights on my motherboard are lit up (indicating that it is receiving power), but the fans won’t turn on, the screen won’t respond, and the LED lights on the RAM sticks won’t glow…. Nothing responds to the power button on my case.

I did check for loose cables and the case power button cable; there were no issues there, but then while I was checking, which took around 5-10 mins with my PSU on, I pressed the power button again just for the sake of it, and my PC started. Then I shut down the computer after it booted to Windows, and I switched my PSU for 2 mins, turned it back on, the mobo LED lights on, and then pressed my power button again. No start... so I just sat there looking at my computer for another 2-5 mins with the PSU switch on, and it happened again. I pressed the power button, and my PC started.

I feel like my PSU is the culprit here. It takes time for it to charge??? or power up to its optimum level...
so rational dission is to change the psu???
like to hear your suggestions

my spec
corsair RM1000x
9900k @5.5
1080ti

thanks

 

[Brainonska511]

Do you have a PSU tester? Could be worth picking one up since they're not so expensive.

You say the board LEDs light up - are there any diagnostic ones lit?

 

[JackMDS]

May be this can help.

https://www.amazon.com/Computer-PC-Tester-Connectors-Enclosure/dp/B076CLNPPK/

 

[C1]

It could simply be the computer start switch. They are known to fail, not often, but often enough.

You can test the PSU start consistency by manually starting it.

To do that, bridge the green wire (pin 3) with a black wire (pin 4) on the 24-pin ATX connector, counting from the right side with the clip facing up; essentially, shorting these two pins together using a paperclip or small piece of wire.

Key points to remember:

- Green wire is the power on signal: This is the wire that initiates the power supply to turn on.

- Black wire is ground: You need to connect the green wire to a black wire (ground) to activate the power supply.

- Check the connector orientation: Always ensure the connector is facing the correct way before bridging the pins.

If the PSU starts consistently, then replace the computer start switch. You should be able to easily buy that part separately unless you have a proprietary computer case.

Good luck