No backlight on laptop [Closed]

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Hello,

I have 2 toshiba P105-S6227 laptops and I'm having a video problem with one not activating the backlight. I've swapped the panels on the laptops and still not able to get the backlight to work. The panel from the faulty laptop works fine on the other laptop. Could this be a motherboard problem or something else? Thanks for any advise that you can give.

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Dear Bear,

Looks much more like a toasted video card.
Thanks for you reply Ambucias but that is not the problem I don't think. This afternoon I swapped the video cards out and the card worked fine in the other laptop. I'm leaning more and more towards a motherboard problem unless someone has some other idea. I've had several laptops before and this is the first time that I've ran across this problem. The video card is working in the laptop because you can faintly see things happening in the lcd and I get video on an external monitor. WEIRD!
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Then it could be due to a faulty inverter
Thanks again but the first thing that I tried was swapping the screens and the screen from the laptop that I'm having problems with worked fine on the other laptop.
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Bear

We have eliminated the following problems:

1. Back light
2. Inverter
3. Video card and driver
4. Cabling

The only thing left is a mummyboard circuit.
Well, a friend came by this morning and he asked if I had switched memory or cpu and said to try that before ordering a MB. I swapped out the memory to no avail - still no backlight. I had a T2060 processor in my junk box so I replaced the T5200 with it and the backlight lit up! Thinking that something might not have been seated right with the T5200, I tried it again and NO backlight. Returned to the T2060 and now I have a working laptop, quite a bit slower but none the less, working. Do you think that the cpu is actually bad or could it be something else? Thanks again for all your help!!
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Dear Bear,

I believe that your deductions are correct, something is shaky in there! How old is it? Was it ever dropped or did someone molested it?
Thats my thinking also. Thanks for your help and time. I've found a board on Ebay so I'll order it. Have a great one!