no signal detected on monitor

Ok, I've been on lots of forums and tried lots of different things, so I'll have to type a lot to bring you helpful people up to speed. Please bear with me. (Specifications at bottom of post)

I recently shipped my computer from China to Australia, I'm now using it with a different monitor since the original broke before I left. When I turned it on the new monitor displayed the "no signal" message and the computer turned off after 10-20 seconds.
I looked inside and found the cpu fan clips had snapped and it was no longer secure, likely due to the ever-delicate Chinese postmen throwing it around.

I duly bought a new CPU fan, attached it securely using thermal grease, and turned on. The computer no longer switches off after a little while (new fan is spinning sweetly), but the "no signal" message is still there on the monitor, suggesting I have a second problem. The led lights and fans are all on (including the fan on the graphics card, and the hard drive is spinning. I hear no beeps of any kind when I turn it on. I also get no lights on the keyboard (nothing when I press caps lock on and off).

I've tried a different monitor, I've tried a different D-Sub cable, and I've tried pluggin the D-sub cable into a Dvi-D adapter and putting that into the Dvi-D socket on the graphics card. Ive also checked for bent pins on the cables. I also know these cables and monitors work since I attached them to an old PC and they worked fine. So, I think the problem must be within my PC itself.

I've also tried turning the computer on with the hard drive and DVD drive unplugged from the psu, still "no signal", so I doubt its anything to do with them. I've also tried reseating the video card and RAM

I've also just tried plugging an old PSU into the motherboard and hard drive and powering up through that, still no luck. Although unfortunately the old PSU has a 20 pin power connector, (my motherboard has a 24 pin slot), and no 6 pin PCI Express power cable to plug into my graphics card, so I still have not eliminated the psu as a problem.

At the moment I therefore think the problem must be with either my graphics card or with my psu. I will try to borrow compatible ones from a friend and test them. One thing I did notice on the graphics card was that the 2nd gold connector from the end is missing a tiny end piece, I don't know if that confirms the graphics card as the problem or not.

In the meantime, are there any other potential problems you could think of? I think I've eliminated everything but the video card and psu, but I may be wrong. Is it possible for it to be a motherboard or processor problem bearing in mind the symptons I'm having?

Thanks for any ideas you have
-Paul

Specifications below

Intel Core 2 Duo E6300 Tray (1.86Ghz/2M)
2x DDR2 512MB (PC2-5300 ADATA)
Hitachi HDS721616PLA380 (SATA2 160GB 7200rpm 8M)
ASUS p5B-VM/C/SI (G965, DDR2, GLAN, VGA, mATX)
Galaxy 7900GS 256MB DDR3 Bulk PCI-E
Aopen COBRA AW850 (CMEDIA CMI8738 PCI Sound)

 

have you tried resetting the bios?
if you don't know how to, remove the power cord, remove the cmos battery, change the jumper near the battery from the 1-2 pins to the 2-3 pins, leave for 10-20 seconds, put it back then put the battery in.
hope it helps =)

 

maybe your computer is set to reconize a larger resolution then what your new monitor can handle start it up wile tapping the f8 key and select vga mode then make your changes in the object in the contrioll panel titled "display"

but thats what i think is going on good luck