Lenovo X200 Backlight LED problem

[woodrick]

I accidentally damage my x200 tablet screen, so i order a new one but when i install the screen the backlight wont turn on!! and i dont know now what to do because the screen was too expensive and i dont want to think in buying a new laptop.

(the screen its new and work fines when my seller test it, i have external video and i have on screen video but very dark)

hope somebody can help, Thank you

[woodrick]

i found the problem and want to share to the forum but at the same time ask for help again.
I found in the motherboard a circuit F7 that its fused and remplace it with a little thin wire and the backlight works but im wooried about what happened if i leave the wire instead of replacing the fuse? and if someone know the part number of de F7 fuse.

[richk]

They have no Lenovo part number. They are not considered replaceable. Having said that, they are made by littlefuse. I don't have an x200 tablet board to look at, but most have a "P" designation, which means 3-amp, 32-volt, fast blow. I tend to move them from other dead boards, but they are sold by "Mouser Electronics" in small quantities and they cost under $1. The lead-free solder is very high-temperature, so most people solder a 2nd fuse on top of the blown one. I would not suggest removing the blown one unless you have a preheater and a good infrared or hot-air rework station.. Here is the page in the mouser catalog:

http://www.mouser.com/ProductDetail/Littelfuse/0466003NR/?qs=sGAEpiMZZMseCiJT91fwIpRk8cYmTOZA4HfWYOo...

[rngkay]

I have the same problem. IBM labs told me that the screen is faulty, so I bought new one but the problem remains. After arguing with the service center, they now say that the MB is dead. The laptop works well, but there is no backlight. Can you please explain where is the fuse located, and is there a way to solder new fuse above the faulty one? I have experience with soldering, and I am familiar with the laptop design.