Solving power problems

Common causes and solutions for power problems are listed in the following table.

Power supply shuts down intermittently.

Cause

Solution

 

 

If equipped with a voltage selector, voltage selector switch on

Select the proper AC voltage using the selector switch.

rear of computer chassis (some models) not switched to

 

correct line voltage (115V or 230V).

 

 

 

Power supply will not turn on because of internal power

Replace the power supply.

supply fault.

 

 

 

Computer powered off automatically and the Power LED flashes Red two times, once every second, followed by a two second pause, and the computer beeps two times. (Beeps stop after fifth iteration but LEDs continue flashing.)

Cause

Solution

 

 

 

Processor thermal protection activated:

1.

Ensure that the computer air vents are not blocked and

A fan may be blocked or not turning.

 

the processor cooling fan is running.

 

 

OR

2.

Open the access panel, press the power button, and see

 

if the processor fan (or other system fan) spins. If the fan

The heat sink is not properly attached to the processor.

 

does not spin, make sure the fan cable is plugged onto

 

the system board header.

 

 

 

3.

If fan a plugged in and not spinning, replace it.

 

 

 

202

Chapter 9 Troubleshooting without diagnostics