Dell 1G155 manual

w w w . d e l l . c o m s u p p o r t . d e l l . c o m

Diagnostic Lights

When you turn on your computer, it performs a series of self-diagnostic tests. A successful power-on self-test (POST) ends with a single beep that signifies the start of normal operation. If the computer fails to complete the POST, a series of lights located on the computer can help you understand which test failed or why the computer stopped responding. These lights communicate problems encountered before and during POST only, not during normal operation. To locate the diagnostic lights, see "Back Panel" on page 46.

The following table lists the code for the diagnostic lights, gives probable causes, and suggests corrective actions.The lights are labeled to help you match the pattern on your computer with ones shown in the table.

B a c k Pa n e l

diagnostic lights

D i a g n o s t i c L i g h t C o d e s D u r i n g P O S T

Light Pattern		Cause
A	off	No electrical power is supplied to the computer.
B	off
C	off
D	off

= y e l l o w

= g r e e n

= o f f

46

Setup and Quick Reference Guide