System Board Built-In Self-Test (M-Bist); Display Panel Power Rail Built-In Self-Test (L-Bist) - Dell Vostro 5502 Service Manual

Table 19. Functions
Purpose
Trigger
Indicator of fault
Repair instruction

System board built-in self-test (M-BIST)

About this task
Steps
1. Press and hold both the M key and the power button to initiate M-BIST.
2. The battery-status light illuminates in amber when there is a system board failure.
3. Replace the system board to fix the issue.
NOTE: The battery status LED does not illuminate if the system board is functioning properly.

Display panel power rail built-in self-test (L-BIST)

About this task
M-Bist
Evaluates the health condition of the
system board.
Press the <M> key and power button.
Battery LED light with Solid Amber.
Indicates a problem with the system
board.
L-Bist
Checks if the system board is supplying
power to the LCD by performing an LCD
Power Rail test.
Integrated into the single LED error
code diagnostics. Automatically initiated
during POST.
Battery LED error code of [2,8] blinks
Amber x2, then pause, then blinks White
x8.
Indicates a problem with the system
board.
Troubleshooting 87