"Compaq.com - Compaq Presario 1600 Series Maintenance and Service Guide - Models: 1650 and 1655

Display is blank and the Suspend icon is flashing.

Internal display is blank and the screen on an external monitor displays information.

System is in Suspend mode.Display function was switched to the external monitor.

Press any key or touch the Touch Pad.

Use Fn + F2 to switch between LCD or CRT.

Problem

Internal display flashes or has garbled characters when computer is connected to external monitor.

Probable Cause

 

Solution(s)

 

 

 

Using 1024 × 768 or higher

 

Restart the computer.
resolution on external

 

 

monitor and have toggled

 

 

back to internal display,

 

 

which supports up to

 

 

800 × 600.

 

 

 

 

 

The light tubes on the edge of the display

 

Improper backlight or

 

Replace the display assembly.
panel do not light up at all and Power-On

 

display cable connections

 

 

Self-Test (POST) completes when the unit is

 

 

 

 

powered up.**

 

 

 

 

 

 

 

 

 

 

 

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

 

Defective system board.

 

Replace the system board.

panel do not light up at all and Power-On

 

 

 

 

Self-Test (POST) does not complete when

 

 

 

 

the unit is powered up.**

 

 

 

 

 

 

 

 

 

Backlight (brightness) cannot be adjusted

 

Improper display cable

 

1. Reseat the display cable to the
with Fn + F7 (¯ ) or

 

connections.

 

system board.
Fn + F8 (- ).***

 

 

 

 

 

 

 

 

2. Replace the display assembly.

 

 

 

 

 

Defective inverter board.

Defective display cable.

Defective system board.

Defective inverter board.

Defective display cable. Defective system board.

Replace the display assembly.

Replace the display assembly.

Replace the system board.

Replace the display assembly.

Replace the display assembly. Replace the system board.

**This problem indicates that the backlight or its power circuitry has failed. Since you cannot observe the POST result on the display panel when the backlight is not functioning, connect the unit to an external monitor before powering the unit up. If an external monitor is not available, verify that POST completes by opening and closing the display, listening for the single or double beep, and watching for the LEDs turn on at the front of the computer.

Problem

 

Probable Cause

 

Solution(s)

 

 

 

 

 

file:///C/SERVICE%20MANUALS/COMPAQ%20_%20chec...1600%20SERIES%201650%20and%201655/solving.html (5 of 8)6/27/2004 2:52:51 AM