Chosen Solution
Hallo everyone, My macbook’s backlight is not turning on please help. The display works fine when i connected to the external monitor. PLEASE guide for me to test : what can i proceed with testing the volatges ? and if there is any fuse failure. I HAVE checked the fuse contunity it seems like backligh fuse is shorted(F9700). i am not able to read any volatges in PPBUS_SW_LCDBKLT_PWR , BKL_EN, like 2.7V Is it because of fuse. need a suggestion before getting one ? Please help.
Firstly, having backlight on an external display wont prove the internal display feed is working. The external display has its own backlight tubs that will be powered from the mains, whereas the data is coming from the MacBook pro. If you have checked the backlight fuse on the main logic board, and it has blown, then something has shorted and caused it to blow. is there any liquid damage on the board, or corrosion of any kind? i’d suggest disconnecting the battery, then inspecting the LVDS cable (display cable that comes through the left hinge) to see if any of the pins on the left side of the socket are charred or damaged. There is the possibility of replacing the fuse on the logic, although it is a component level repair, but its pointless doing this replacement without first tracing the cause of the fault. There will be some damage somewhere, unless it was an unusual power spike that blew it. See what you can find, and if you find any damage, include some photos here and i’ll see if i can help in any way.
