Postagem original de: Cmd ,
Just to add to this, I have had a few of these where one of the first 3 pins are damage on the ribbon cable (mainly second) I'm not sure which pins it is off the top of my head, but 2 of them hook directly to the back light leds and have 2 large solder points. Ideally if you can find where the pin on the ribbon cable goes to on the logic board, you could solder some 30 gauge wires to connect them and tape and/or glue them down to the ribbon cable. I have not found where they go to yet, but I am working on finding it since i have around 3-4 that have ribbons messed up pretty bad and only thing suffering is the back light. Also as strong posted, if the coil tests bad (should read around 0.5 ohms) then that would cause it. Last option is to use a multimeter and find a point on the board the supplies 6-9v DC. On the few I have took readings on, they run around 8.5v for med brightness. These repairs require good soldering skills and most likely a multimeter. If you are not skilled with either, I would say to throw it on ebay and buy another, or buy one on ebay in hopes of a good logic board (get a broken screen one and replace it with yours, even with it broken it should still have a back light!).