Interpreting POST Diagnostic Front Panel LEDs and Audible Codes

This section covers the front panel LED codes as well as the audible codes that may occur before or during POST that do not necessarily have an error code or text message associated with them.

WARNING! When the computer is plugged into an AC power source, voltage is always applied to the system board. To reduce the risk of personal injury from electrical shock and/or hot surfaces, be sure to disconnect the power cord from the wall outlet and allow the internal system components to cool before touching.

NOTE: If you see flashing LEDs on a PS/2 keyboard, look for flashing LEDs on the front panel of the computer and refer to the following table to determine the front panel LED codes.

Recommended actions in the following table are listed in the order in which they should be performed.

Not all diagnostic lights and audible codes are available on all models.

Table A-2Diagnostic Front Panel LEDs and Audible Codes

Activity

Beeps

Possible Cause

Recommended Action

 

 

 

 

Green Power LED On.

None

Computer on.

None

Green Power LED flashes every None

Computer in Suspend to

two seconds.

RAM mode (some models

 

only) or normal Suspend

 

mode.

None required. Press any key or move the mouse to wake the computer.

Red Power LED flashes two

2

times, once every second, followed by a two second pause. Beeps stop after fifth iteration but LEDs continue until problem is solved.

Thermal protection activated:

Air flow is restricted, a fan may not be functioning, or the heatsink is not properly attached.

1.Clean the air vents on the front, back, or any other vented side of the computer.

2.Ensure that there is a 10.2 cm (4 in) clearance on all vented sides of the computer to permit the required airflow.

3.Ensure that computers are not so near each other that they are subject to each other's re- circulated or preheated air.

4.If the computer is within an enclosure, ensure that there is proper intake and exhaust ventilation for the enclosure.

5.If a message appears on the screen indicating that a fan is not working, replace the fan.

6.Ensure that the heat sink is properly attached.

Red Power LED flashes three

3

times, once every second, followed by a two second pause. Beeps stop after fifth iteration but LEDs continue until problem is solved.

Processor not installed (not

1.

Check to see that the processor is present.

an indicator of bad

2.

Reseat the processor.

processor).

106 Appendix A POST Error Messages