Chosen Solution
Hello. Story short … I’ve blown a few components near the LCD connector on the main logic board.
I need to find the parts on ebay so that I can replace them. From what I can find on YouTube and Google. It seems to be some kind of filter or a fuse (that I’m not so sure yet). From a thread on IFIXIT someone has similar problem and got help to identify the component as L4400 a 120 Ohm 3A fix inductor (ferrite bead). So I wonder if it is the same case for mine. As it seems to be the cause that the LCD does not get power, and thereby CPU load of 100% and fan spinning non stop (source from youtube repair of similar case). If you can point me to something I can buy on ebay or aliexpress I would really appreciate your help. Thanks in advance. Update (05/15/2019) Multimeter Diode mode reading on one fo the pad
I changed the blown component (L4400 a 120 Ohm 3A fix inductor (ferrite bead)), which was ordered from ebay for 6 bucks, for a whole stack of it. I soldered (sloppy job, but well it was my first time) it to the logicboard and there were no more issue with the screen and fan.
I think you will need to discover and correct whatever issue caused the components to blow in the first place, as well as trace out the whole path to verify that other components haven’t also been damaged in a less-visible manner. Schematics: http://schemalaptop.blogspot.com/2016/11…
Thien Khanh Nguyen you are right about the component being L4400 a 120 Ohm 3A fix inductor (ferrite bead) . The next component right by it is F4400 or the fuse for the LCD power circuit. Power comes directly to it via PP12V_S0_LCD from the S0 rail. My suggestion is to clean the board check the fuse for continuity and replace the blown component after you check it with your meter between on of the solder pads and to ground. Use your meter in diode mode. Red probe to ground, black probe to a solder pad on L4400 and let us know what value you get. Then check with your meter in resistance mode and see if you have any continuity between the pads (red probe to pad and black to ground) and ground, which you should not have.
