Pc doesnt show anything on my monitor

Hello,
im having the same problem as a lot of people in here. ive done the eraser trick (found a faulty slot actually :/ ), and the cpu heat test (passed), but it still didnt boot up. when i hit the power button, the fans rev and the drives all boot up, but my monitor fails to receive any kind of information. i cleaned the dock and copper plates on my gforce 8800gts graphics card, and cleaned all the adapters/cables from the power supply all the way to the monitor input cable, but still when i turn my monitor on it only says "no signal."

any help would be appreciated.
the mobo is good, ram is good, cpu is good. i cant test the hdd because i cant use my monitor ><