[chinguz]

Alright so the other week my PSU died and so i went to get a new one. After installing the PSU i noticed the audio and usb ports were not working. i reinstalled drivers and afterward i formatted but to no avail. anyway so i just left it as it was... the other day the computer's cpu mem was at a constant 100% all used up by the system and the pc eventually froze. after a restart the monitor did not turn on at all and that was that.
I put the primary hdd into another pc to get the important stuff and it seemed fine (no mem usage problem) so it must have been the hardware on that pc.. dunno.

anyway, today i moved the the gfx card, psu and secondary hdd into another pc of mine (which is pretty much identical).
this computer ended up having problems too.. everything seems to run fine but the monitor will not turn on. I've checked if the gfx card, psu, hdd, ram was the problem by switching them out with other ones, but problem still persists. (Monitor works fine btw)

note: - both pcs had 350watt PSU and this new one is 650watts
- on the old pc the power button on tower ended up malfunctioning so that's why I've swapped everything to another.
- cleaned all the dust and made sure all the wires & stuff are connected properly.

my problem is why the monitor is not turning on? maybe the motherboard is screwed? seems that the new PSU screwed stuff on both pcs. either way its hard to pinpoint the problem

Any ideas i could try?
i'd get a professional to look at it but thought i'd try asking first .. plus i don't plan to get ripped off.

[awdark]

Lets assume you got all the hardware working. Like the computer is working.

You should make sure your monitor is plugged in. If anything, unplug the video cable then plug the power in. Some monitors make you turn them on... and when you do, it should display a "No signal detected" type error on the screen if that shows up, then at least your monitor hardware is okay.

Then follow the video cable and make sure its connected. The video cables sometimes can come loose from the back when you move them around a lot so double check that.

If possible and I think you have confirmed it already, try a known working video source like a laptop or a different computer.

[chinguz]

yeah i've tried that, works on none of the monitors i have.
seems odd the first time around when the monitor didn't show up and i've not touched anything.

the tower that worked perfectly fine, i've put all the original pieces back into it and now the monitor doesnt show up either. seems the PSU after i've installed it did something.

[erniehkwon]

BIOS could be corrupted? Find out if your BIOS can be reset to factory settings. Then setup the monitor to the onboard video port. Try to start with minimum hardware. So, can you see the BIOS bootup display or is that turned off in BIOS? Can you see the amount of RAM at bootup? Motherboard older than five years? Good reason to upgrade motherboard, CPU and RAM.