My son dropped his Compaq Presaris B3800, and the LCD screen no longer works. The computer works fine with an external monitor - which leads me to think that he has damaged the LCD screen backlight. Any ideas / notes / pictures on how I can remove the old backlight and replace it? Where can I purchase a new one online?

Your laptop may have a combination of problems. Since the laptop was dropped, it is possible that your may a motherboard that no longer outputs video through the video controller, or the screen may have been damaged internally. Try hooking up an external monitor through the vga output of your laptop, usually located on the side or back of the laptop. If the external monitor works, then most likely it is your screen that's bad, if the external monitor doesn't works, then most likely it is your motherboard that's bad.


Let me know if this helps.

it is an issue with the LCD on your laptop as you get a fine display on external monitor
either get it repaired from a local technician
or get the LCD replaced

hi there,
Please have it plugged it onto an external monitor to make sure that the problem is not with the LCD. Is there a backlight on the LCD or is it totally dark?
If the external monitor gives out an image it means that the LCD might be busted but do you know the keyboard shortcut to switch between the external monitor and the laptop screen?
You can try FN+ F5. if that does not work you definitely have to try it out on a external monitor.

Sounds like your CRT is dying. Sometimes older ones can take longer to turn on, I would suggest upgrading to an economy LCD, they're pretty cheap.

By using an external monitor, you have shown that the computer/video adapter is fine.
I'm wondering if you have told the computer to send the image to the LCD screen--using the Fn key and the special function key combo that directs the image to the LDC, the external monitor, or both.

It could also be the connection of the LCD monitor to the motherboard. You would do well to check that connection.

First instinct would tell me that your LCD has gone bad. A refurbished replacement LCD should run around $300-$325 give or take.

Keep us posted, good luck

God Bless

-Carlos:

Hi,

The display properties indicate the hardware is working, so it's likely just a setting.

On HP/Compaq models you will see a picture, usually on the F4 key that looks like a screen with two lines beside it.

You need to hold down the Fn key(bottom left) and then push the F4 key at the same time to cycle between LCD, external or both.
If it is a newer model, a menu will pop up when you do this asking if you want to duplicate the LCD on the external, switch to the external or extend the desktop onto the external. Select the appropriate setting or continue holding down Fn while pressing F4 to cycle between the settings to the one you want.

If you have re-installed the computer at some point with anything other than the factory recovery set this may not work and I will have to give you a longer set of instructions.

If this works please rate this as fixed, if not reply back and indicate what version of windows you're using and I will post the instructions for the "long" way.


Chris

Make sure the laptop's external VGA port is turned on. There will be a function key somewhere on the keyboard (location varies by manufacturer and model) that controls the connector. If the connector has gotten turned off the external monitor will go to sleep because it's not getting any input.

If the cable from the laptop is connected to the TV, you've selected the VGA input and see no signal, you probably haven't enabled the laptop's VGA output connector. Somewhere on the keyboard will be a function key with a little monitor screen on it. Hold down the F or Fn key and press the monitor key and it will switch on the external monitor connector. On some monitors, the first press shuts off the laptop screen when it turns on the external connector. If yours does that, press the key a second time to turn the laptop screen back on.

the LCD screen is damaged.

hope this helps