Hi, this is my first board repair ever. This is my personal learning project to learn microsoldering and troubleshooting boards. I don't get paid for it. I'm trying my best not to be stupid.
Having a 820-00840-A with liquid damage. Don't now the exact story behind this MacBook. The battery has corrosion on its board and was disconnected with kapton tape from the logicboard. Seems that someone worked on it already (maybe it was a Genius).
The board has some corrosion on the F4800 area and as well on Q7065 and also next to Q8030. I think that most of the board had contact with water, because I can clearly see some calcification all over the board which may come from dried water (I highlighted this in one of my uploads). I can scrape the white stuff from the contacts or clean it with PCB cleaner. Never seen something like that on Louis videos before.
Not so good looking caps are C7650 and C7470 but the corresponding rails are not shorted.
* PPBUS_G3H is there with 13.1V
* P5VS4_VSW is 0V
* PP5V_S5 is 0.15V
* There is a short to ground on P3V3_S5. I get 0.5 Ohm resistance to ground on that rail.
My first question: what should I do next?
I started the investigation on P3V3_S5. I have learned from Louis Videos that I can inject voltage to a rail to find out what is shorted. When I set my Power Supply to 1V and limit the current to 2A it only uses 0.4V. Nothing gets warm. Should I increase the current? I don't want to roast anything there. Or should I check a different rail?
Having a 820-00840-A with liquid damage. Don't now the exact story behind this MacBook. The battery has corrosion on its board and was disconnected with kapton tape from the logicboard. Seems that someone worked on it already (maybe it was a Genius).
The board has some corrosion on the F4800 area and as well on Q7065 and also next to Q8030. I think that most of the board had contact with water, because I can clearly see some calcification all over the board which may come from dried water (I highlighted this in one of my uploads). I can scrape the white stuff from the contacts or clean it with PCB cleaner. Never seen something like that on Louis videos before.
Not so good looking caps are C7650 and C7470 but the corresponding rails are not shorted.
* PPBUS_G3H is there with 13.1V
* P5VS4_VSW is 0V
* PP5V_S5 is 0.15V
* There is a short to ground on P3V3_S5. I get 0.5 Ohm resistance to ground on that rail.
My first question: what should I do next?
I started the investigation on P3V3_S5. I have learned from Louis Videos that I can inject voltage to a rail to find out what is shorted. When I set my Power Supply to 1V and limit the current to 2A it only uses 0.4V. Nothing gets warm. Should I increase the current? I don't want to roast anything there. Or should I check a different rail?
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