Question System won't power on ?

[Grim-UK]

Hi All,

This is an interesting one, I'm not sure if it's Mobo or PSU, but here's the specs and what's happening:

ASUS TUF x570 Plus WiFi
Ryzen 7 3800x
8x8 Corsair DDR4
RTX3090
EVGA 1000G PSU

As of last week the system won't power on via the button on the case. I've known the button to get pushed too far so checked that but all ok. I've even shorted the power pins directly on the mobo, still nothing. AC in to the PSU is fine.

If I jump pins 4 and 5 on the ATX connector, everything powers up, but no POST. Of course if I remove the jump it powers off. So here's the strange thing, if I jump it and press the on button, I get to POST. I can also remove the jump and the system stays on. I can even boot into OS (at least I can backup!). If I then shutdown, everything completely powers off (usually RGB is still on, but not now) and the on button no longer works again. I can only jump start it as above.

I've re-seated components. Reset cmos to defaults. Gone down to 1 stick of RAM in A2. No joy.

I've been leaning to a CPU upgrade and this has helped that get under way, but wondered if anyone had any thoughts on what this could be? Thanks in advance.

 

[Lutfij]

Welcome to the forums, newcomer!

How old is the PSU in your build?

if I remove the jump it powers off.
Please elaborate. You keep stating jump, what is this jump you speak of?

According to your motherboard manual, here, page 3-22, Section 3.11.3, your board has a feature to revive a board in case the BIOS is corrupt. See if that helps bring your board to life, with the aid of the latest BIOS version on a USB drive meant for flashing.

 

[Grim-UK]

Hi Lutfij,

Thanks for the quick response and welcome.

The 'jump' is a link (paper clip) between pins 4 and 5 on the 24pin ATX connector that will cause the system to power up. Once the system is powered, I can press the on button and it will start to POST and boot. But the on button will not work unless I 'jump' pins 4 and 5 first.

The PSU is from 2015. I must admit this is older than I thought but it still powers everything after I jump the ATX pins.

I will also take a look at the revive feature, although I can get the system to boot ok, as long as I make the link between the ATX pins to initially power the board first.