Troubleshooting Without Diagnostics

Solving Power Supply Problems

Solving Power Supply Problems

Problem

Cause

Solution

 

 

 

Power supply shuts down

Voltage selector switch

Select the proper AC voltage.

intermittently.

on rear of computer

 

 

 

chassis not switched to

 

 

 

correct line voltage.

 

 

 

 

 

 

Power supply fault.

Replace the power supply.

 

 

 

 

Computer powered off

Processor thermal

1.

Ensure that the computer air

automatically and the

protection activated:

 

vents are not blocked and the

Power LED flashes Red two

A fan may be blocked

 

cooling fan is running.

times, once every second,

or not turning.

2.

Open hood, press the power

followed by a two second

OR

 

button, and see if the processor

pause.

 

The heatsink/fan

 

fan spins. If the processor fan is

 

 

 

 

not spinning, make sure the

 

assembly is not properly

 

 

 

fan's cable is plugged onto the

 

attached to the

 

 

 

system board header. Ensure

 

processor.

 

 

 

the fan is fully/properly seated

 

 

 

 

 

 

or installed.

 

 

3. Replace the processor fan.

 

 

4.

Reseat processor heatsink and

 

 

 

verify that the fan assembly is

 

 

 

properly attached.

 

 

 

 

Power LED flashes Red,

Power failure (power

1.

Check that the voltage selector,

once every two seconds.

supply is overloaded).

 

is set to the appropriate voltage.

 

 

2.

Open the hood and ensure the

 

 

 

4-wire power supply cable is

 

 

 

seated into the connector on the

 

 

 

system board.

 

 

3. Check if a device is causing the

 

 

 

problem by removing ALL

 

 

 

attached devices). Power on the

 

 

 

system. If the system enters the

 

 

 

POST, then power off and

 

 

 

replace one device at a time

 

 

 

and repeat this procedure until

 

 

 

failure occurs. Replace the

 

 

 

device causing the failure.

 

 

 

Continue adding devices one at

 

 

 

a time to ensure all devices are

 

 

 

functioning properly.

 

 

4.

Replace the power supply.

 

 

5. Replace the system board.

 

 

 

 

D–4

360201-002

Service Reference Guide, dc5000