MacBook Air 820-00165 PPBUS-G3H Short to ground

[technowiz]

Hi. I am in need of some assistance. I am trying to track down a short in this board and I am having limited success. Fuse F7140 is blown and I have removed U5450, R5450 as well as fuse F7700 and the short disappears past these components but I am unable to locate it. The only thing I can think of is that it has an internal short within the board. Any help would be appreciated. Thanks

[gmorb]

Insert voltage?

[mawaqas]

did you find out what was causing it?

[AtoZed]

Hey!
I have solved this type of issue once before on this exact board. Pin one side of F7140 was getting the 8.6v but the pin 2 side was shorted to ground. The fuse was blown as well. I didn't have the means to inject voltage so I replaced the fuse. Once I did that the pin 1 side of the fuse became shorted to ground as well. I then plugged in the magsafe and dripped alcohol all over the board to see if anything got super hot. This is when I found C7313 sizzlin'. After replacing it, I got fanspin and the board was fully functional. The short was gone. Hope this helps. There are a lot of capacitors on the G3H line that could be blown and shorting to ground.

This is my first post. I wanted to post regarding sourcing the F7140 fuse. I have another Air with a similar issue and don't have any fuses left on donor boards.

[Neodim]

Originally Posted by AtoZed

...... dripped alcohol .....

good solution, sometimes I also use this technique

[ktmmotocross]

Originally Posted by Neodim

good solution, sometimes I also use this technique

standard technique if u dont have thermocam