Hi all, I apologise if this is the wrong forum section to ask this question as this is my first time posting here.

I have an ASUS P4SGL-VM/WOL motherboard that came with an old Packard Bell PC. It was working fine when I got it in 2023 and it worked for a while after that, but now it suddenly will not boot into BIOS or make any beep codes.

Originally I noticed that when I powered it on while trying to reinstall Windows 98 SE, the hard drive activity LED on the front was orange and there were no beeps. I thought something might just have been unplugged so I opened it up and accidentally knocked some cables out of the HPANEL1 header on the motherboard.

I managed to find the motherboard manual and reconnect those cables but the issue remained. I also replaced the CMOS battery and waited, but that did not help. I have tried removing the RAM as well, but still no change.

What happens now is:

* I press the power button
* The system powers on
* CPU fan and PSU fan spin normally
* The motherboard green LED is lit
* The top CD-ROM drive LED comes on
* Sometimes both CD-ROM drives start blinking, then stop
* The fans keep spinning, but there is still no display, no BIOS screen and no beep codes

I am starting to suspect the PSU might be dying, or that something on the motherboard has failed. I have ordered a PSU tester and plan to take everything apart properly to test it when it arrives.

These were the specs from the eBay listing:

* CPU: Celeron 2.66 GHz
* Memory: 768 MB RAM
* Graphics: 32 MB integrated
* HDD: 18.6 GB PATA
* NIC: RTL8139
* ODD1: 52x CD-ROM
* ODD2: 52x CD burner
* FDD

Does this sound more like a PSU issue, a motherboard issue or something else? Also, should this board still beep if the case speaker is connected correctly? The connector for the speaker from the motherboard goes to the front of the case where the PATA hard drive is for some reason meaning it can't get to the cables properly unless I remove the entire HDD, though I’ve tried swapping the cables around to see if it would make a difference (it didn’t).

Usually I have the side panel off when testing all the internal stuff but it seems when I flip one of the connectors on the HPANEL1 for the LED at the front and I switch on the PSU, the orange LED shows up on the front of the PC but goes away when pressing the power button