820-00426 smc area started smoking after plugging in battery


New member
I have this 15" MBP Retina which says this is a 2016 version when I google the LB number. When I got it initially it would would not turn on with the battery plugged in so I had to unplug the battery, plug the charger in and hit the power button for it to turn on. The power button was kind of inconsistent. I was able to boot as guest user and plug the charger in and it said to "replace now".

I got the new battery but before plugging it in I removed the logic board and put flux and heated the corroded areas of the keyboard connector as well as around R9192/U9600.

The ISL6259 area around the battery current sensing were all damaged so I replaced the ISL along with all the caps/resistors on the right side(C7101 to R7152).

I had to use a schematic for an 820-3787 since I don't have a schematic for this model. I believe they are very similar judging by the donor board I am using.

After all that I went to test this out. I plugged in the display cable, keyboard cable and the new battery and while I was in the process of plugging in the trackpad cable I started seeing smoke come from the SMC area and I quickly unplugged the battery.
Things smelled burned and the keyboard backlight part was slightly melted right around the smc area which is why I know the smc was the fault.

I removed the edge bonding and saw that Pin 2 of L5001 and Pin 1 of C5001 both have burned pads. Again I had to use a 820-3787 boardview to find that out and I am not sure where I can run a wire for those since the pad is gone.

Now when I plug in a charger I get no light on the charger.

I'm not sure why the SMC area would smoke up like that when there was no liquid damage around it nor did I do any repairs in that area. All I did was plug in a battery.


New member
I don't know why I didnt think that was an issue. I didn't get to plug the trackpad cable in before it started smoking.
I've never replaced an SMC before nor do I have the tools. Could you advise me on where I should get the tools and if its possible for me to take an SMC from an 820-3662 or 820-3787 because I don't have a donor for this board number.


You need an exact donor board. You need experience, so practice on scrap board. I assume Louis has videos on replacing SMCs. Links to reball stencils are in the Tools section.