Question PC Build Stuck on Flashing Underscore

[GregB99]

I have bought parts for an XP gaming build. I have:

Gigabyte GA-H61M-DS2 Motherboard
Intel i5 2400
Kingston KHX1333 Blu 8gb DDR3 kit
430w Corsair PSU
Radeon HD 7770 1GB GPU

The PC boot loops - fans spinning up for a second and then turning off - a few times and then it will boot into a black screen with a flashing underscore.
I have no bios screen, no power to PS2 or USB keyboard to try F2 or DEL. USB stick lights up for a second then nothing.

It does this despite:

• Trying both ram modules singularly and together
• Trying a GPU or the mobo's VGA for output
• Taking out the CMOS and reinserting it, or changing the CMOS battery
• Changing the PSU power lead
• Having a HDD plugged in or not
• Having a bootable USB plugged in or not
• Reseating RAM
• Reseating the CPU
• I cannot see any bent pins on the mobo's CPU socket

Is this more likely a dead motherboard or CPU? All parts are used but all 'were tested' before I bought them by the respective sellers.

I guess it could also be RAM? I can get a hold of some other DDR3 ram but I dont have it with me at the moment.

Any ideas would be appreciated.

Thanks,

Greg