I recently swapped out my mobo with a newer one and when I turn the PC on, I get no video input from onboard or the graphics card, and no post beep either. I've checked the VGA cable, it works. I've tried removing the video card and just using onboard, it didn't work. I've tried resetting the CMOS, didn't work. I can't actually test to see if it's the PSU or not because I don't have an extra one laying around, but I have used this PSU in a different mobo that had a 20-pin connector but this new mobo has a 24-pin connector.
Any suggestions on how to fix it?
EDIT: The PSU has a 20-pin connector with an extra 4-pin one so that it works with older and newer mobos. It also has a 12V connector to go to the mobo. I have all of them plugged in in the right order. The 12V connector and the 20-pin connector works, but I don't know if the extra 4 pins to make a 24-pin connector works. I can't test the voltage because it has to be plugged in.