Troubleshooting an HP Power Supply

If your Hewlett-Packard PC is experiencing power issues, it’s quite possible there may be a problem with the Power Supply Unit (PSU).  The power supply is inside the PC and is exposed at the back of the computer.  The external view of the power supply shows the cord that goes to the wall socket and will often have a l / 0 switch and a red voltage regulator switch that indicates 115 and 230.  Some HP models will also have an indicator light. Try the following to troubleshoot the power supply:

1. Make sure the l / 0 power switch at the rear of the power supply unit is in the l position.
2. Unplug the power supply at the rear of the PC, and then press the power button on the front of the unit.  Plug the power supply back in and see if it works.
3. Replace the power cord with another known good cord.  This is the same type of cord your monitor uses.
4. Clean the unit.  You can vacuum or air-blast the outside of the unit to remove dust and hair debris.  Vacuuming the outside is preferred as blowing will cause the debris to go into the power supply.
5. Try plugging the cord directly into the wall.  Do not use power strips as they may have failed.
6. Toggle the voltage regulator switch from 115V to 230V then back again.  If you are in North America, this switch must be on 115V.
7. Lastly, you may need to go inside the case and confirm the thin wires running from the front power and reset switches are connected to the motherboard.

If your PSU has an indicator light

1. Indicator light should be solid and not flashing.
2. If the HP power supply is flashing, disconnect everything inside.  If the LED is still flashing, the power supply is probably bad.
3. If the LED is completely off, then the power supply is probably bad.