I have had same trouble -
Setting up HTPC GA-H55M-UD2H board, i3 540 CPU, Corsair TW3X4G1333C9A ram.
Antec SLI 500w power which is absolutely fine, was until recently runnung dual AMD CPU, Supermicro MB, 2 SLI cards - Vanilla PCIe card
Spins fan, light on MB blink then shuts off, cycles through this till I turn off power
BTW there are no beep codes at all.
Tried with and without graphics card, swapped ram to other slots, bettery out etc.
This is the first time in a long build career that I have experienced this sort of trouble. I notice that the ram i am using is not actually on the supported vendors ram list on the Gigabyte Web site for this motherboard but I would be surprised if it was that (who knows)
Its a Saga Now