Help! blank screen.....

[highoaker]

Hello, My system was running well until I installed a wireless PCI adapter. Then I couldn't boot it any more, nothing appeared on the screen and no beeps; it was total silence, though the CPU fan and the Chassis fan were still working.
I tried to boot with only mobo(with onboard graphic), cpu and ram, but it didn't work.
I replaced the ram, no use.
I replaced the PSU, no use.
I even replaced the mobo and CPU, but same thing happened.
What could be the problem?
Thanks in advance.

 

[monkeysweat]

try just booting with NOTHING except the cpu, see if you get any beeping, then try with adding the RAM

--- remove CMOS battery first for 5 minutes, then start this process after putting battery back in