Chosen Solution
Hi iFixit, The backlight on my MacBook Pro 15’’ Late 2013 went down. Following the instructions from Backlight fuse and wled driver location on logical board a1398 2014post, I located the fuse on the logic board and checked it with a multimeter - it is OK and not blown. No spills or mechanical damage anytime in past. I read that the LED backlight failure in LCD assembly is extremely unlikely, can anybody confirm that? The other point of failure is the logic board with backlight driver IC. Is there any diagnostics for it? I cannot even find a part number for it. The one from the other post seems to be Apple’s proprietary. The cost of LCD assembly is about same price as logic board. I don’t want to buy both to see which one failed. Is there any other way to figure out the source of failure? Any thoughts are greatly appreciated
Remove the logic board and check for liquid on the back of the board. Even though you say liquid has not been spilt on this, I have had many MacBooks come in where the customer swears this is the case, yet there is liquid damage… The backlight IC is very robust in the Retina models and very rarely fails, it is not like the BGA LP8550 on the Airs. I have only ever had to replace 2-5, and only due to being visually burnt or liquid damaged. Backlight issues with the screen can happen, but only if liquid is spilt over the screen in most cases, to get on the screen’s PCB. Check pin 1 of the LCD connector to see what voltage you are getting for backlight (whilst the screen is plugged in). This will give an indication of the issue.
