PC issue with video not showing

[johnhende]

My desktop computer recently died on me. When I turn it on nothing shows up on the monitor. The fans and power are on (everything lights up at least) but there's nothing there. Then when I try to turn it off by holding the power button in it won't turn off. The only way to turn it off is to flip the power supply switch. Here's what I've tried so far:

- Made sure it's not the monitor by testing the monitor on my laptop (it's fine)

- Reset the mother board by re-seating the battery

- Tested with another power supply (same result)

- Rearranged the RAM (same result)

- Tried a new motherboard (same result)

- Removed drives and started the computer (same result)

- Switched out cpu with another cpu (same result)

- Tried to use a POST card (POST card didn't even show a message on it's LED)

So, that's where I'm at. Any help would be greatly appreciated!

[Rik_]

Are you using a graphics card or built in graphics? Does the motherboard have a system spaeker attached to it?

[johnhende]

I have a Radeon 5770 that I use. I'm not aware of a system speaker on the motherboard.

[Rik_]

So, it could possibly be the graphics card at fault then!

What motherboard have you got? I need it's make and model number, and do you have the manual that came with it?

[johnhende]

It's a Gigabyte MA78GM-US2H and yes, I still have the manual. Also, I forgot to mention that I plugged the monitor into the motherboard graphics and the result was the same. So, I'm not sure it's the graphics card.

[Rik_]

Ok, that's information you haven't given before. You say you tried another PSU and another motherboard but did you try the replacement motherboard WITH the replacement PSU? It's quite possible that one blew and took the other out!