ASRock Fatal1ty 990FX Killer not working, no video, no beeps, holding down power not turning it off

[BBCG]

Hi,
I have
an ASRock Fatal1ty 990FX mobo,
FX 8320E processor,
SAPPHIRE FleX Radeon HD 7770 1GB gpu,
LOGISYS Computer PS550E12BK 550W ATX12V psu.
2x8GB HyperX Fury dimms

When I power on all the system fans started, the HDD start but I don't see any video - not even the bios screen.
What I have tried, all of which did not work
1. cleared the cmos (i) using jumper (ii) removing battery
2. removed the memory (i) all dimms (ii) left only one dimms, (iii) combine with step 1.
3. changed the monitor cable
4. changed monitor, (i) combine with steps 1. & 2.
5. changed hdd (i) combine with steps 1 & 2.
6. cleaned and re-greased processor (ii) changed heatsink, (iii) combine with steps 1, 2, 4 & 5
7. removed from chasis, put on a bench, with only the psu and gpu and jumped started the system, still nothing.

I'm out of ideas.
Please can any one help. I'm open to all suggestions.

I've already tried doing a handstand whilst pressing the power button but would have felt silly adding that to the list

 

[Calvin7]

You'll need a PSU with a minimum of 450W capacity.

I can see a picture of the power supply label at Newegg. It has only a single +12v rail rated at 25Amps.
Watts equal amps times volts equals 300 watts

See if you can find a QUALIITY 550 watt power supply with a single +12v rail rated at 25Amps.

Heres a Coolermaster
+12V@45A
http://www.newegg.com/Product/Product.aspx?Item=N82E16817171092

Cheap power supplies have their wattage on the 3.3v and 5v lines.

 

[BBCG]

This was very bad advice. I used my Rosewill Photon-850, PHOTON Series 850W Full Modular Power Supply, 80 PLUS Gold Certified, Single +12V Rail PSU from my gaming rig on ASrock mobo and it killed the PSU. The ASRock mobo f*** up the PSU. So the now I have to buy another PSU I'm now wondering if the mobo damaged the 2 other PSU I used on it.

 

[BBCG]

I can now absolutely confirm that the mobo damaged the PSU. I tried a Corsair CX500M and the thing literally smoked it. Smoke actually came from psu end of mobo power cable. I'm left worrying if it damaged the processor, memory or graphics card.

I'll shall never again buy an asrock mobo and if I should ever again even touch one, may I be quartered, maimed and my head be put upon a pike as a warning to others.