820-01598-A Liquid Damage (Working almost fine)

Customer reported this macbook as dead, however we were able to turn it on.
9 out 10 times the mac turns on and boots ok, 1 time wont turn on, you need to try again and it turn on.

I will reflow the affected areas and use the ultrasonic cleaner. You think this is the correct approach?
Also, one of the most affected areas is the U3900 zone but it has a big soldered shield, you think ultrasonic would be enough?

I reflowed the affected aread and cleaned with ultrasonic
Then the macbook only took 5V.

I reflowed again U3200 and U3100 and the computer took 20V and turned on just 1 TIME.

What should I measure?

C6902 and C6905 got completely destroyed, do you think these missing caps could be affecting? (Just for testing for sure)


Staff member
The missing caps shouldn't be a problem; there remain more filter caps.
Not easy to repair a board with advanced corrosion...