Compaq 1600XL - Manual (Page 76)

28 T ROUBLESHOOTING P RESARIO N OTEBOOK M AINTENANCE AND S ERVICE G UIDE 1600XL S ERIES
Presario 1600XL Series
Model 1600T, 1600-XL140, 1600-XL141, 1600-XL142, 1600-XL143, 1600-XL144,
1600-XL146, 1600-XL147, 1600-XL150 XL156, XL157, XL255, XL256, XL257, and XL258
**This problem indicates that the backlight or its power circuitry has failed. If the backlight
is not functioning, the POST result cannot be observed. Connect the unit to an external
monitor before powering up the unit. If an external monitor is not available verify that POST
is complete by opening and closing the display, listening for the single or double beep, and
watching for the icons to turn on at the front of the notebook.
The light tubes on the
edge of the display
panel do not light up
at all and Power-On
Self-Test (POST) does
not complete when the
unit is powered up.**
Defective system board. Replace the system board.
Backlight (brightness)
cannot be adjusted
with Fn+F7 or Fn+F8.
Improper display cable
connections.
1. Reseat the display cable to the
system board.
2. Replace the display assembly.
(Continued) Defective inverter board. Replace the display assembly.
Defective display cable. Replace the display assembly.
Defective system board. Replace the system board.
Solving Display Problems Continued
Problem Probable Cause Solution(s)
This display panel has
a continuous pattern
across it (e.g.,
“jailbars” pattern), has
a single color on it, or
has garbled graphics
across the entire
panel. This failure is
for patterns across the
entire panel (not just
on one section).
Improper display cable
connections
Reseat the display cable to the
following until the problem is
solved:
1. System board
2. Display assembly
Defective display cable. Replace the display assembly.
Defective inverter board. Replace the display assembly.
Solving Display Problems
Problem Probable Cause Solution(s)