Checking Your PSU

If the wall outlet and the power cord are lovely, make positive the connection at the motherboard is secure. Then you must face the fact that the power supply itself is bad. If you have a Multimeter you can check the power supply output before purchasing a new. Simply follow these steps.

Turn off the PC, but do not unplug it, open the technique unit. Set the multimeter to read DC volts in the next range higher than 12 volts. Locate a power connector similar to the hard drive or cdrom drive connector that is unused & turn on the PC.

You can also unplug a drive connector & use it as well. Turn on the PC & insert the BLACK probe in to the power connector on of the BLACK wires. Touch the RED probe to the YELLOW wire on the power connector.

The multimeter reading ought to be +12 volts. Now touch the RED probe to the RED wire & the reading ought to be +5 volts. If no readings or different readings occurred, you must replace the power supply. If the readings were correct, you ought to check the P8 or P9 connectors at the motherboard. These connectors may even be named P4 & P5.To check these connectors, perform the following...

Insert the BLACK probe in to P8 at of the BLACK wires. Insert the RED probe in to the P8 connector at the RED wire. The reading on the multimeter ought to be +5 volts

Check the power going to the Motherboard connections by inserting the RED probe in to P8 at the YELLOW wire & you ought to get +12 volts. Leave the BLACK wire touching the black wire at the P8 connector. Check the BLUE wire & the reading ought to be a -12 volts.

Now move the BLACK probe to the BLACK wire on the P9 connector. Test the WHITE wire by inserting the RED probe & the reading ought to be -5 volts. Check the RED wires on the P9 connector & you ought to get +5 volts on each red wire. You won't get exactly or 12 volts but the readings will be close, such as.02 volts.

If the Power Supply is a couple of volts off, in either direction, such as when the RED wire ought to be reading -5 volts but it reads -8 volts, or if there is no readings, replace the power supply.

DO NOT remove the power supply from the technique unit case when performing this tests.DO NOT performs these tests in the event you do not feel comfortable. Be positive to remove any & all electrical static build-up from your clothes & body BEFORE touching any parts inside the technique unit. And NEVER open the power supply case for any reason, since high voltage may be present.