ATroubleshooting
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
Activity | Beeps | Possible Cause | Recommended Action |
|
|
|
|
Green Power LED On. | None | Computer on. | None |
|
|
|
|
Green Power LED flashes. | None | Computer in Suspend to | None required. Press any key if a keyboard is |
|
| RAM mode (some models | attached or move the mouse if a mouse is |
|
| only) or normal Suspend | attached to wake the computer. You can also |
|
| mode. | wake the computer by pressing the power button |
|
|
| or tapping the touch screen. |
Red Power LED flashes two | 2 | Processor thermal |
times, once every second, |
| protection activated: |
followed by a two second |
| Fan may be blocked or |
pause. Beeps stop after fifth |
| |
| not turning. | |
iteration but LEDs continue |
|
until problem is solved. | OR |
| |
| The heatsink/fan |
| assembly is not properly |
| attached to the processor. |
1.Ensure that the computer air vents are not blocked and the fan is running.
2.Open the cover, press the power button, and see if the fan spins. If the fan is not spinning, make sure the fan's cable is plugged onto the system board header.
3.If the fan is plugged in, but is not spinning, then replace heatsink/fan assembly.
4.Contact an authorized reseller or service provider.
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 | 1. | Check to see that the processor is present. | |
(not an indicator of bad | 2. | Reseat the processor. | |
processor). | |||
|
|
Red Power LED flashes four | 4 | Power failure (power | 1. | Ensure the DC power cable is plugged into |
times, once every second, |
| supply is overloaded). |
| the I/O panel. |
followed by a two second |
|
| 2. | Check if a device is causing the problem by |
pause. Beeps stop after fifth |
|
| ||
|
|
| removing ALL attached devices (such as a | |
|
|
|
|
Interpreting POST diagnostic front panel LEDs and audible codes 33