Testing an ATX PS
Testing an ATX PS
Hello all, can someone tell me how to test an ATX power supply? I am pretty sure it can be done by putting a jumper wire between two of the wires on the mother board connector and plugging it into the wall but I have no idea which leads on the connector to jump. Any help is appreciated
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Executioner
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Got this off of Google search http://groups.google.com/ (use at your own risk)
First, disconnect everything from the power supply (including MB.) Plug AC cord into the rear of the PS. IF the PS has its own rocker on/off switch, turn it ON. There should be +5v on pin 9 of the 20 pin connector (+5vsb, usually a violet wire.) There should be >0.8v on pin 14 (PS-ON, usually a green wire.) This is from an internal pull-up to the +5vsb.
Connect PS power leads to 1 or 2 IDE HDs (for a load). Jumper pin 14 (PS-ON) to pin 13 (ground, black wire.) At this point, fan in PS should start spinning, drives should spin, and + 5/12v, -5/12v, +3.3v, and
+5vsb should be present at 20 pin connector.
Disconnecting pin 14-13 jumper should turn supply back off.
and another one:
1. Disconnect the main connector of the PS from the mother board. Leave the CD, hard disk, and other components connected. (A load must be on the PS in order to test it.)
2. With the PS plugged in, test the voltage on connection #14. Test by placing one lead from your multimeter into pin 14 on the main connector, touch the other lead to ground. (use one of the screws
attaching the PS to the chassis as the ground contact) You should read 5v. If not you have a PS problem.
3. If you read five volts the PS is producing the correct power-on voltage. Normally when you press your power on switch this voltage is shunted to ground ( goes to zero) this signals the PS to supply power to the other connections. You need to ground pin 14 in order to continue trouble shooting.
4. Using one lead from your multimeter, or a wire with bare ends, touch one end to connection 14 and the other to ground. The PS should start. (fan will come on etc)
5. If the PS starts you will need to make a temporary ground to pin 14 to test the other connectors. Press the exposed end of a wire into connection 14. Use a toothpick or something similar to wedge the wire into the connector. Screw the other end of the wire to the case. Now your hands are free to test the other connections.
6. Using your multimeter test each connection for the proper voltage, See the attached diagram. Touch one probe to the connection, the other to ground. If all 20 connections read correctly (no less than 90% of specified voltage), your power supply is working properly.
7. If your power supply tests ok you have a switch or MB problem
8. To bypass the switch, disconnect the switch from the MB. Place a bare end of your ground wire into connection 14 on the main PS connector. Bend the wire along the side of the connector, hold it in place, and plug the connector into the MB. Attach the other end of the wire to a ground screw and plug the PS in. If the switch is bad your system should boot up and run normally. You can replace the switch or you can make your pin 14 ground wire permanent and use a power strip to turn you PC on and off.
9. If your PC does not boot you may a MB problem or a component problem. Make sure you have a good ground connection to PIN 14 on the main PS connector. Unplug the PS and remove all adaptor cards(modem, video, etc) from the PC. Plug in the PS, if the PC boots you have a problem with one of the adaptor cards. If the PC does not boot , unplug each of your drives one at a time. If the PC still will not boot you have a MB or CPU problem.
First, disconnect everything from the power supply (including MB.) Plug AC cord into the rear of the PS. IF the PS has its own rocker on/off switch, turn it ON. There should be +5v on pin 9 of the 20 pin connector (+5vsb, usually a violet wire.) There should be >0.8v on pin 14 (PS-ON, usually a green wire.) This is from an internal pull-up to the +5vsb.
Connect PS power leads to 1 or 2 IDE HDs (for a load). Jumper pin 14 (PS-ON) to pin 13 (ground, black wire.) At this point, fan in PS should start spinning, drives should spin, and + 5/12v, -5/12v, +3.3v, and
+5vsb should be present at 20 pin connector.
Disconnecting pin 14-13 jumper should turn supply back off.
and another one:
1. Disconnect the main connector of the PS from the mother board. Leave the CD, hard disk, and other components connected. (A load must be on the PS in order to test it.)
2. With the PS plugged in, test the voltage on connection #14. Test by placing one lead from your multimeter into pin 14 on the main connector, touch the other lead to ground. (use one of the screws
attaching the PS to the chassis as the ground contact) You should read 5v. If not you have a PS problem.
3. If you read five volts the PS is producing the correct power-on voltage. Normally when you press your power on switch this voltage is shunted to ground ( goes to zero) this signals the PS to supply power to the other connections. You need to ground pin 14 in order to continue trouble shooting.
4. Using one lead from your multimeter, or a wire with bare ends, touch one end to connection 14 and the other to ground. The PS should start. (fan will come on etc)
5. If the PS starts you will need to make a temporary ground to pin 14 to test the other connectors. Press the exposed end of a wire into connection 14. Use a toothpick or something similar to wedge the wire into the connector. Screw the other end of the wire to the case. Now your hands are free to test the other connections.
6. Using your multimeter test each connection for the proper voltage, See the attached diagram. Touch one probe to the connection, the other to ground. If all 20 connections read correctly (no less than 90% of specified voltage), your power supply is working properly.
7. If your power supply tests ok you have a switch or MB problem
8. To bypass the switch, disconnect the switch from the MB. Place a bare end of your ground wire into connection 14 on the main PS connector. Bend the wire along the side of the connector, hold it in place, and plug the connector into the MB. Attach the other end of the wire to a ground screw and plug the PS in. If the switch is bad your system should boot up and run normally. You can replace the switch or you can make your pin 14 ground wire permanent and use a power strip to turn you PC on and off.
9. If your PC does not boot you may a MB problem or a component problem. Make sure you have a good ground connection to PIN 14 on the main PS connector. Unplug the PS and remove all adaptor cards(modem, video, etc) from the PC. Plug in the PS, if the PC boots you have a problem with one of the adaptor cards. If the PC does not boot , unplug each of your drives one at a time. If the PC still will not boot you have a MB or CPU problem.