Sometimes when a computer refuses to power up, it’s due to the power supply going bad. Here’s a safe way to test power supplies.
One day my pastor called me up because he had a computer problem. He knew his power supply was dead but didn’t know what to do about it. So his computer’s mortal remains are sitting here amongst my moving boxes as I write.
The answer, of course, is to call Dave and ask him to look at it. And then Dave will plug his spare ATX power supply into the system and see if it powers up and doesn’t smell weird.
With my power supply, the system powered up and was fine. The Hipro 146-watt power supply that came in his system from the factory had given up the ghost.
But what do you do when you don’t have a spare ATX power supply and Dave lives too far away and is too busy moving and doesn’t owe you a favor?
You unplug all the power supply’s power leads. Then you pull the power plug from the back of the unit. Turn off the power supply’s power button on the back if it has one. Then you grab a paper clip. Bend the paper clip into a U shape. Find pin 14 (the green wire) and connect it to any of the ground wires (black). Make sure the paper clip is far from anything that it can short out. Plug the power supply back in. If necessary, throw the power switch in the back.
If the fan starts, the power supply is good and the problem is something else.
Most likely if it’s not the power supply it’s the motherboard. Or maybe you got lucky and the lead from the computer case’s power switch came disconnected from the motherboard. I’ve seen stranger things–like a BIOS chip in a friend’s 386 way back when that managed to creep halfway out of its socket and render the system unbootable.
Sometimes just pulling the plug and waiting 30 seconds or so fixes intermittent power-up problems. Some power supplies are more prone to this than others..
But in this case, the dinky 146-watt power supply had had it. I went to the nearest store, picked up a house-brand 300W power supply that fit, and all was good. For 20 bucks, he was back up and running again.