Stumped by POST fail - GPU BIOS beep differs

[Moonpenguin]

Ok so here's the thing; I've spent a lot of time researching this problem on these (and other forums) and I'm a bit stumped.

I've built a system for my nephew which was working when I wrapped it for Christmas. Details are below.

MSI 970A-G46 Mobo; AMD Phenom II X4 965 Black Edition 3.4GHz CPU; Cooler
Master RS-500-PSAP-J3 PSU; 2 x 4Gb Corsair XMS3 DDR3 1600MHz DIMM 240-pin CL9
RAM; ASUS HD 7770 2Gb GDDR5 GPU

Now I have it back after a slow decay of functionality that started with games dropping out, moved to blue screen of death and has finally ended up with no POST.

I have isolated the issue (I believe) down to the graphics card. I get one long and two short beeps with no graphics card, the same with the graphics card in the second (lower) PCI-e slot and no beeps at all with the card where it should be, in the uppermost PCI-e slot.

The card was bought new but seems to have displayed all the symptoms of a slow death. The question is, if the card was truly faulty, shouldn't I get a BIOS error telling me so rather than silence when booting?

All ideas warmly received; I just want to be sure I have identified the problem correctly before I return the graphics card.

Cheers all )

 

[HugoStiglitz]

This tends to happen with the card is not totally stuffed but stuffed enough to not work.

The motherboard is waiting for a signal back from the GPU on boot to say its all ok and display is working. its obviously working to the point where the motherboard knows there is a card in the slot (so you don't get no GPU beeps - long & short beeps) but not working to the point where it gives the ok signal back to the motherboard.

You can even get GPU's that will send back the good signal to the mobo the machine post beeps to say everything is ok but nothing displays on the screen.
Try a different GPU in that system or try that GPU in another system.