cm wrote in
:

I would appreciate it if someone would tell me how to test an atx
power supply with digital volt meter. (how to rig the atx plug to
turn on the supply so I can check it)

So you load down the outputs and turn on the ps and measure the
voltages. If one of the voltages is off, you'll know the ps is bad.
But what if all the voltages are within spec? Can you conclude that the
ps is OK? No, you can't! Because all the voltages may be OK for hours,
then one of them has a glitch. Your PC may not run well under those
conditions. And you may never see it, even if you stare at your
voltmeter for hours. Conclusion: substitute a known-good ps. (Power
supplies are cheap.) If your PC problems go away, be happy.