Dell Latitude LCD wont light up

Hello..
I have a Dell Latitude Cpi with 13.3 inch screen. The LCD wont light up and I am wondering where to start to diagnose the problem. What is the most likely culprit? LCD inverter, Cable, or the LCD itself? I plan on buying used parts from eBay and was hoping to get it right the first time.
Any suggestions?
Thanks
Hammer

 

So the Laptop posts OK?
You have no screen illumination during the BIOS post?
I haven't tried on my laptop, but I presume the screen brightness keyboard command has no effect till windows boots. In other words this keyboard command isn't set to dim? Even on dim you should still have some screen resolution.

How old is it. It could be the backlit flourescent lighting has gone, but these should last for several year, unless it has been switched on and off many, many times a day, then like any flouro it may have blown. I would take it to a service agent and ask their opinion. It would be worth a small fee to be sure.

 

Thanks for the reply, Paul
The laptop belongs to a friend so I don't know a lot of specifics. She bought it used and working from corporate surplus and thinks it's about 4 years old. She took it to a computer shop to have it checked out and they told her it was the backlight and would cost more to fix than buy a new computer. Sounds to me like they were trying to sell her a new laptop.
The screen shows no illumination at all... ever. With no illumination I cant tell if it is posting or not.
Without knowing a whole lot about these, I figured I could just replace the LCD but was unsure whether the cable and the inverter might contribute to the problem.
I do, however, have an identical computer thats works perfectly. Would you suggest swapping parts to help identify exactly where the problem lies, or am I asking for trouble by doing that?
I have replaced the MB and most of the plastic on the "good" laptop so I'm familiar with how to disassemble and reassemble it with no problem. Its the diagnosis that has me stumped.
Thank you for your help.
Hammer

 

You certainly have more experience with disassemble and reassembling laptops than me. I guess it's your call. If the screen cable is easy to unplug it might be worth a try. I guess there is no TV out connector? Even if there is, it probably needs to be switched in software, which isn't going to help in your sutu.

Sorry to ask the obvious. But there is power on to the unit?

 

I have seen this before.

First, try applying a small bit of pressure to the left hinge area. The ZIF connector is at / below the hinge area. If this doesnt work and you do have a replacement system to trade parts with, replace the LCD screen.

Use caution when handling the ZIF connectors as they can and will tear. (ZIF means zero insertion force) Handle with care and dont apply too much pressure when inserting them in to their connection as they also have fragile connection points.

Unfortunately removing the LCD means basically taking half the laptop apart and putting it back together. Its really not that difficult, just alot of tiny screws that need to be put in a secure location so that they dont get lost in the carpet.

Cheers~