Pc won't turn on - new psu did nothing

[unwashed potato!]

My pc has decided to just completely die. Zero power nothing. I figured was the psu and just tried a brand new one, and still nothing. Absolutely zero signs of life.

What can I do to troubleshoot?

One thing to add, last time my pc was running, it was frequently making the noise as though a usb device was being unplugged. It would do this about every 10 minutes, and this was while it was sat doing nothing other than being logged into a user and left alone.

Has hoped this meant the psu was failing to get power properly around and the first thing to go with low power is usb devices but perhaps I'm wrong.

Any help appreciated

 

[covenantuk]

Any boot LED code? Or just completely nothing?

If nothing then suspect dead board

 

[hornetstinger]

Usual thing, test PSU by itself, does it power up? Does another PSU work? Does that "faulty" PSU work on another board?

Ideally you want two PSU's, two motherboards, and/or a PSU tester.

 

[drakulton]

Remove GPU and try to start the PC..

 

[Tetras]

Any boot LED code? Or just completely nothing?

If nothing then suspect dead board

Agree. If there's no signs of life whatsoever and a new PSU didn't fix it, the motherboard is probably a goner.

It might be worth trying out of the case.

One thing to add, last time my pc was running, it was frequently making the noise as though a usb device was being unplugged. It would do this about every 10 minutes, and this was while it was sat doing nothing other than being logged into a user and left alone.

Did you disconnect all the USB headers?

 

[unwashed potato!]

USB headers

What are these?

 

[Tetras]

What are these?

The ones that connect to the motherboard from the case, since they can take rough usage sometimes and a short is possible on one.

 

[neojay]

Might be worth pulling every USB device out of the PC, I have seen this be the cause of a PC not booting at all.

 

[Begbie]

Unplug literally everything, expect the power headers (or short them to turn on) and see if you get anything. If not, probably the motherboard. Even if so, still probably the motherboard.

 

[freddie64]

Failing power switch on the case, or loose wires? Not sure if this would cause the USB unplug sound though.

Try shorting the power pins on the motherboard with a screwdriver.

 

[unwashed potato!]

Failing power switch on the case, or loose wires? Not sure if this would cause the USB unplug sound though.

Try shorting the power pins on the motherboard with a screwdriver.

Tried that first and nothing

 

[unwashed potato!]

motherboard gigabyte ga ab350 gaming 3

This is the motherboard I have. What should I be looking for to replace? Would you need to know what cpu and gpu I have?

 

[mickyflinn]

motherboard gigabyte ga ab350 gaming 3

This is the motherboard I have. What should I be looking for to replace? Would you need to know what cpu and gpu I have?

What CPU you have as some early CPUs loose support with newer bios and chipset ?

Would you like WiFi And Budget for board.

 

[unwashed potato!]

What CPU you have as some early CPUs loose support with newer bios and chipset ?

Would you like WiFi And Budget for board.

AMD Ryzen 9 3900X looks to be the most recent cpu I have on my order list so assume it's this.

I have a WiFi add on so wouldn't need that. Budget honestly I'd rather not be spending much on this, but can be sold in the benefits of more expensive

 

[mickyflinn]

AMD Ryzen 9 3900X looks to be the most recent cpu I have on my order list so assume it's this.

I have a WiFi add on so wouldn't need that. Budget honestly I'd rather not be spending much on this, but can be sold in the benefits of more expensive

B450 , a520 , b550 motherboard should do , could put an add in the wanted section of the members market. If you go used make sure you check what CPU there using , 3000 and above yo know it has the correct bios

You can get an A520 for about £50 but they tend to have no vRM heatsink ai if you push the 3900x it mite throttle.

 

[unwashed potato!]

B450 , a520 , b550 motherboard should do , could put an add in the wanted section of the members market. If you go used make sure you check what CPU there using , 3000 and above yo know it has the correct bios

You can get an A520 for about £50 but they tend to have no vRM heatsink ai if you push the 3900x it mite throttle.

Thanks. What could I get within the £120 - £150 mark?

 

[mickyflinn]

Thanks. What could I get within the £120 - £150 mark?

I would get the Gigabyte B550 AORUS ELITE V2 which can be had for £90 no need to spend anymore than that.

 

[freddie64]

Few other things to try before you buy.

When you swapped the PSU did you use the new kettle lead?

If using a surge protector, try plugged straight into wall socket.

Try a different wall socket.

 

[Rroff]

Have you tried booting with just one stick of RAM at a time? though usually even with faulty RAM you will get an initial POST attempt with the fans spinning up even if it immediately turns off again.

 

[unwashed potato!]

I would get the Gigabyte B550 AORUS ELITE V2 which can be had for £90 no need to spend anymore than that.

Delivered today. Put it in and fired up using old PSU.

However I can't get any of the screens to show anything, and can't get mouse or keyboard to show any power, and keyboard is backlite so should at least show that. Plugging mouse and keyboard into my laptop works fine. Plugging in my streamdeck into any USB slot works no issues. So wtf that's about I've no idea

Also holding down the power button on the case no longer turns the pc off. It turns the pc on but only way to power down the pc is switch it off from the psu button. When folding the cases power button (the one on top that turns the pc on), after a few seconds it starts flashing so it recognises that I'm holding the button, just then it doesn't do anything

Any suggestions what I've done wrong?