Specifications

P
RESARIO
N
OTEBOOK
M
AINTENANCE AND
S
ERVICE
G
UIDE
1400 S
ERIES
T
ROUBLESHOOTING
25
Presario 1400 Series
Models: XL240, XL241, XL242, XL244, XL245, XL246, XL247, XL250, XL340,
XL341, XL342, XL343, XL344, XL345, XL346, XL350, XL352, XL355, and XL356
Continued
Solving Display Problems
Problem Probable Cause Solution
The light tubes on the
edge of the display
panel do not light up,
and the Power-On
Self-Test (POST)
completes when the
unit is powered up.**
Improper backlight or display
cable connections
Replace the display assembly.
Defective inverter board Replace the display assembly.
Defective display cable Replace the display assembly.
Defective display panel Replace the display assembly.
Defective system board Replace the system board.
The light tubes on the
edge of the display
panel do not light up,
and the Power-On Self-
Test (P OS T) doe s n ot
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.
Defective inverter board Replace the display assembly.
Defective display cable Replace the display assembly.
Defective system board Replace the system board.
**This problem indicates that the backlight or its power circuitry has failed. Since you cannot
observe the POST results on the display panel when the backlight is not functioning, connect the
unit to an external monitor before powering it up. If an external monitor is not available, confirm
that POST completes 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.