Interpreting Power LED and Beep Codes
This section covers 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.
Color
LED/Beep Activity
State/Message
Green
On
(S0) Computer on
Green
1 blink every 2 secs
(S1) Normal Suspend Mode
Green
1 blink every 2 secs
(S3) Suspend to RAM
Clear
Off
(S4) Suspend to Disk (if applicable)
Clear
Off
(S5) Computer off
Green
Green when flashing ROM
Boot block recovery with embedded video
Red
CPU Fan weak (RPM < 1000) or not turning.
Display Warning message and long beep for 5
secs and shut down.
CPU thermal shutdown (weak CPU fan speed or
not running)
Red
5 flashes, once per second, followed by 2
second pause. 5 beeps.
No memory installed/Pre-video memory error
Red
6 flashes, once per second, followed by 2
second pause. 6 beeps.
Graphics card error (Pre-video graphics error)
Red
8 flashes, once per second, followed by 2
second pause. 8 beeps.
System board failure or invalid ROM basing on
checksum
120 Appendix C Troubleshooting Without Diagnostics