Origineel bericht door: Mike Miller ,
To those of you who have no backlight on an LED lit macbook - The problem is most likely related to the WLED driver on the logic board not supplying power. Power output from the WLED driver ranges from something like 18-26 volts. most other circuitry on the board runs at 12v or less, so liquid spills do not damage other parts on contact. your lvds cable is most likely fine. there is a fuse on the logic board that runs the WLED driver. it is normally located close (within 2cm) of the lvds connector, and is a 0402 package (the smallest on the board, will look like a surface mount resistor or capacitor). on my macbook (nonpro, 13.3") it was a brown fuse with a small white dot in the center. can also be black, or have an "f" in the center. measuring both sides of this fuse with the macbook power on should read 12v. if not, the fuse is bad. you CAN just remove the fuse and close the circuit with a blob of solder, however if there is still a short in the system (remaining traces of liquid spill, residue, etc) and you short this fuse, you will destroy the WLED driver chip. these need to be replaced by a micro electronics professional, with a hot air gun and microscope. your best bet is to find someone good at soldering (very, very small) and order some replacement 0402 package fuses and solder in a replacement. if the fuse is good, pin1 of the wled driver should be receiving ~3v to power up the wled driver. if fuse is good and still no output from wled driver, then the wled driver itself is most likely damaged. you can search around the net, there are a few chinese forums with schematics and pictures of the macbook logic boards to help you with this.