Why my computer doesn't beep or post ?

[andrianramones]

i just bought a new mobo and then my pc powers on but no beeps from motherboard, fails to boot, monitor is blinking, cpu, case fans and graphics card fan are spinning. optical drives open and close. Have reset bios jumper, removed battery. removed all ram apart from slot 1, removed and put back graphics card, unplugged all drives, unplugged power cord and pressed power button to discharge any power. nothing works.
cannot switch power off once pc is switched on have to remove power cord from the back.

Is it about PSU ?

here my spec.

Asus P5G41T-M LX socket 775
Intel Core 2 Duo
Asus Nvidia GT 430
Cooler Master PSU 460w

thanks and please help

sorry for the spec i just new in PC.

 

[flank21]

do you have the 4pin cpu power pugged into the motherboard?

 

[andrianramones]

yeah i already plugged...still dun know what the probs...what do you think ?