My sister bought a Compaq laptop a couple years ago and its LCD has gone bad. When external monitor was plugged in, it works fine so it was something related to LCD. I found some articles online describing the same issue and determined that I have 2 options. Option 1. buy a new LCD for about $150. Option 2. identify a bad part and replace it under $20. Since I like experimental stuff I decided to try Option 2!!
Symptom was the following. LCD comes up in a very pinkish screen when the system boots up and after a few seconds it goes very dim, almost black. If I use light, I could see something is displayed on the screen. It seems that the backlight which gives brightness to the LCD was the bad part.
The problem is narrowed down but there are still 2 possibilities. First is the inverter that converts and supplies high voltage to LCD, and the second is the CCFL backlight. I digged in a bit more and found out that when inverter goes bad or burned out, screen should not even come up when the system boots up. It stays dark all the time because inverter does not supply the power at all. However, pinkish screen is a very common indication that backlight is about to die. I was able to confirm this by taking backlight from another LCD and plugged it into this LCD. Good backlight gives bright white light while bad backlight gives pinkish light at first and light goes off in a few seconds.
I ordered a CCFL backlight for $15 including S&H and it was delivered in 2 days. I opened up LCD and carefully disassembled the bottom part of the LCD – backlight is located at the bottom.
A few screws had to be unscrewed and some tapes and foils had to be removed; however, remember where they should go and keep them as clean as possible if you need to reuse them. Once outer cover was removed you should be able to locate the backlight and its reflection material. Make sure the reflection panel is not bent or damaged in the process because it is quite important in order to have even light distribution. You will see what happens when this is damaged at the bottom of this page.
Old backlight was removed from the LCD as the following and a connector, wires, and white rubber cover at both ends were removed from old backlight because I had to reuse them. Little soldering was needed because new light came with just the light. I had to solder the wires to the both end of the light.
Now the new light was inserted back into the LCD but bent reflection panel caused this uneven light distribution at the bottom of the screen.
I re-did the reflection panel because it was very annoying and the following is the screen with re-surfaced reflection panel.