Although PSUs are designed to only work while connected to a motherboard, you can bypass this by using a small length of wire. Commonly known as the paper clip test, this shortcut offers you the ability to check that the PSU is receiving power without using the motherboard.
How do I test my ATX power supply?
To test your PSU:
- Shut off your PSU.
- Unplug all cables from the PSU except for the main AC cable and the 24-pin cable.
- Locate pin 4 and pin 5 on your 24-pin cable.
- Bend your paper clip so the ends can be inserted into pin 4 and pin 5.
- Turn on the PSU.
- See if the PSU fan turns.
How do I test a power supply without a multimeter?
The Answer
- Plug the power supply into the wall.
- Find the big 24-ish pin connector that connects to the motherboard.
- Connect the GREEN wire with the adjacent BLACK wire.
- The power supply’s fan should start up. If it doesn’t then it’s dead.
- If the fan starts up, then it could be the motherboard that’s dead.
Can I check my power supply without opening case?
No, not unless you can read the label information from outside the case, and I don’t think that’s possible. Unlike the motherboard or processor, the PSU isn’t intelligent, so you can’t run software that will interrogate it and find out what it is. You have to open the case and read the label.
How does an ATX power supply work?
To put it in layman’s terms, the switch you press in front of your case causes a ‘jump’ in those two pins which in turn tells the power supply to turn on. The above picture is the general design of an ATX plug. The green box and black box are the exact locations on the plug we will be working on.
Why does my Motherboard only have one ATX plug?
Get another PSU just to power those specific components. As most of you know, motherboards usually come with just one ATX plug. How that works is, the two pins on the row of your motherboard is usually connected by a momentary switch.
What is the green wire on an ATX plug?
The green wire on ATX plug is the “power on” line and is pin #14. The standard ATX plug will also have seven ground, or black wires.
How do I know if my power supply is bad?
When you press the power button on your case, it jumps the green wire to a ground, telling the PSU to turn on. When this “jump” is broken, the PSU shuts off. The green wire on ATX plug is the “power on” line and is pin #14.
