Console turns on then after 3 seconds back off

I have a console that once it is plugged in the red light comes on. When the power button is pressed it "turns on" the console. The fan runs during this period, then after 3 seconds the console and fan turn off with no beeps no lights. If I press the power button it resets the console back to standby and the red light turns back on.

I have checked for the YLOD which it does not appear to have. I replaced the power supply, but produced the same results. I have also removed the board and am not able to find a spent compositor.

Any help would be appreciated, thanks in advance.