Interpreting POST diagnostic front panel LEDs
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 10-2 Diagnostic 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 | Processor thermal |
times, once every second, |
| protection activated: |
followed by a two second |
| A fan may be blocked or |
pause. Beeps stop after fifth |
| |
iteration but LEDs continue until |
| not turning. |
problem is solved.
OR
The heat sink/fan assembly 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 heat sink/fan assembly.
4.Contact an authorized reseller or service provider.
Red Power LED flashes three | 3 | Processor not installed (not | 1. | Check to see that the processor is present. |
times, once every second, |
| an indicator of bad | 2. | Reseat the processor. |
followed by a two second |
| processor). |
pause. Beeps stop after fifth iteration but LEDs continue until problem is solved.
