Solving Power Problems

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

Table 2-2Solving Power Problems

Power supply shuts down intermittently.

Cause

Solution

 

 

Voltage selector switch on rear of computer chassis (some

Select the proper AC voltage using the selector switch.

models) not switched to correct line voltage (115V or 230V).

 

 

 

Power supply will not turn on because of internal power supply

Contact an authorized service provider to replace the power

fault.

supply.

 

 

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:

A fan may be blocked or not turning.

OR

The heatsink is not properly attached to the processor.

1.Ensure that the computer air vents are not blocked and the processor cooling fan is running.

2.Open hood, press power button, and see if the processor fan spins. If the processor fan is not spinning, make sure the fan's cable is plugged onto the system board header.

3.If fan is plugged in, but is not spinning, then replace the heatsink/fan assembly.

4.Contact an authorized reseller or service provider.

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

Cause

Solution

 

 

Power failure (power supply is overloaded).

1.Open the hood and ensure the 4- or 6-wire power supply cable is seated into the connector on the system board.

2.Check if a device is causing the problem by removing ALL attached devices (such as hard, diskette, or optical drives, and expansion cards). 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 that is causing the failure. Continue adding devices one at a time to ensure all devices are functioning properly.

3.Replace the power supply.

4.Replace the system board.

14 Chapter 2 Troubleshooting Without Diagnostics

ENWW