|HELP| Computer shuts off on starting windows screen or after about 20 seconds

lord tone

Honorable
Jan 12, 2014
5
0
10,510
hello chaps , in dire need of help here (ive searched everywhere)
first post ( im new to toms hardware)

so about a month ago i put together a system , its the fifth system ive built so im fairly experienced with building computers specs below:

CPU: AMD A10 6800K APU
CPU Cooler: Cooler Master Hyper 212x
Motherboard: ASUS F2A85-M
Memory:2x4gb of Kingston HyperX blu
Storage: 1TB seagate barracuda 7200
Case: Zalman Z3 plus
Power Supply: Corsair CX500M
Optical Drive: samsung something

so this computer turns off after about 20 seconds regardless, whether it be BIOS or starting windows.. BUT occasionally it will boot into windows . however if the ram is not in it doesnt turn off , if the bios chip is not in it doesnt turn off. the power supply has been put in a friends system and it runs fine so i know it cant be the PSU, the cpu has been put in another system and it runs fine also, so it cant be the CPU. ive tested the ram with other ram of the same type and it still turns off. it also does the turn off thing with the stock cooler and with the Cooler Master hyper 212x and it does it whether there is a HDD in it or not
AND for the breif 20 seconds i can get into BIOS menu the temperatures do not go above 30-40 degrees Celsius so it cant be a heat problem..
so through the process of elimination i found the problem HAD to be the motherboard, so i sent it back to my retailer (Mwave AU) and they sent the board to ASUS . after 2 weeks of doing the warranty deal they sent the board back claiming that they found no fault so i really need help here

Yes the ATX 12v cable is in , and yes the 24+4 pin or whatever connection is in securely please respond ASAP

THANKYOU
 

lord tone

Honorable
Jan 12, 2014
5
0
10,510

well, i tried using the motherboard's EZ Flash utility 2 and it shutdown when i selected to use that tool
and also if something goes wrong (it shuts down during the process of flashing) couldn't i just buy a new BIOS chip
they're like $20 or something
 

lord tone

Honorable
Jan 12, 2014
5
0
10,510


okay so every time i get into bios and click the "EZ Flash Utility" option, it shuts off
every time without fail it waits for me to click it, unless of course coincidence