PC won't boot after interrupted memtest

[x0]

Hey!

I dd'd a bootable USB for installing Gentoo on my very old computer. I tried the memtest, which got stuck after a while. I gave up and turned off the power to my system. Ever since then, I have been unable to boot into the system. I don't see the BIOS screen when I turn on the computer, and the screen always shows the 'No signal' message.

Steps I have taken to identify issue:
1. Disconnected hard drives, CD drive, and floppy drive. (No change)
2. Removed both ram sticks, and checked booting with each one separately. (No change)

Motherboard: Intel D845GVFN
Processor: Intel Pentium 4 (2.4 GHz)
RAM: (512 + 128) MB

Any help is appreciated. Thanks in advance.

[cboldt]

Power supply or MoBo.

[x0]

I checked the +5V and +12V lines with a multimeter. They're fine. Besides, I can see the CPU fan running.
How do I check the motherboard?

And I'm concerned about the timing here. Everything worked fine right before the memtest. I had Arch installed on my hard drive which worked just fine.

[cboldt]

Well, pretty much no matter what you are doing when a system gives up the ghost, will appear to have been the culprit. You happened to be running memtest.

Do you get any beeps when you fire up the system? As you describe things, powerup does nothing on the video side, not even able to get to BIOS screen or not seeing the BIOS "flash screen." I suspect some sort of hardware failure. I'm not sure that voltage on the P/S is a good indicator of P/S health either. The voltage needs to hold under load, and needs to be "clean enough."

The only tools most of have to figure out if a MoBo is good, is to swap it out. I had an ASUS A7N8X Deluxe that I was fond of. It gave up "one day, out of the blue, for no reason," and the probable wearout was nothing more than capacitors. Running fine (a 24/7 machine), went down for an acceptable reason (either I wanted to run a new kernel, or power outage, or something), and would not restart. Grabbed some random old MoBo from the stack, and it ran - this ruled out P/S as the source of trouble.

[NeddySeagoon]

x0,

It has to be hardware related. Since you have a multimeter, check PWR_GOOD from the PSU.
That will hold the CPU reset if its false. I don't know if it should be high or low for normal operation.

Next step is to unplug all the bits that plug into the motherboard, except the CPU and PSU.
Even with no RAM it should beep at startup.

Now add things back until the beeps stop. The last thing added back, that stop the beeps, is probably faulty.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[x0]

It's the motherboard. I borrowed my friend's computer and swapped parts until only the motherboard remained.

I don't suppose Pentium 4 processors are in high demand in the market these days which given my situation is quite disappointing.
Anyway, thanks for your help cboldt, and NeddySeagoon.