It's definitely possible this was your issue all along. Corrosion occurs instantaneously, but if it's only a small amount of moisture, it can become worse over time. Even if the MacBook was powered off, voltage is still present in many places. It could have been the damage was too small to see at the time of initial inspection.
For now, I would ignore the capacitors, you can come back to them if need be. They may be functional after the cleaning.
Your issue is going to be the resistor (R7552). U7501 is a Power IC and the resistor is specifically on the Enable Pin for the 3v3 side of the chip. Enable lines are particularly important, for obvious reasons. If the chip isn't being told to turn on, then it just doesn't.
The resistor in question is a 0 ohm resistor, which basically means it's like a fuse. It's a wire, unless something goes wrong. You can verify this with your multimeter by checking for continuity between the two test points on either side of the resistor. If they are not continuous, the resistor itself will need to be replaced. In theory, you can replace it with a jumper wire, but I tend to recommend against that as a permanent fix since it will not blow like the resistor, which could prevent damage to the chip if there was an issue upstream.
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Since this is a 0201 size component, godspeed if this is your first microsoldering repair. It's doable. But those little suckers are tiny. A hot air station and flux will be your best friends. [br]
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Since this is a 0201 size component, godspeed if this is your first microsoldering repair. It's doable. But those little suckers are tiny. A hot air station, fine point tweezers, and flux will be your best friends. [br]
Good on you for getting this far![br]
[br]
It's definitely possible this was your issue all along. Corrosion occurs instantaneously, but if it's only a small amount of moisture, it can become worse over time. Even if the MacBook was powered off, voltage is still present in many places. It could have been the damage was too small to see at the time of initial inspection.
For now, I would ignore the capacitors, you can come back to them if need be. They may be functional after the cleaning.
Your issue is going to be the resistor (R7552). U7501 is a Power IC and the resistor is specifically on the Enable Pin for the 3v3 side of the chip. Enable lines are particularly important, for obvious reasons. If the chip isn't being told to turn on, then it just doesn't.
The resistor in question is a 0 ohm resistor, which basically means it's like a fuse. It's a wire, unless something goes wrong. You can verify this with your multimeter by checking for continuity between the two test points on either side of the resistor. If they are not continuous, the resistor itself will need to be replaced. In theory, you can replace it with a jumper wire, but I tend to recommend against that as a permanent fix since it will not blow like the resistor, which could prevent damage to the chip if there was an issue upstream.
Since this is a 0201 size component, godspeed if this is your first microsoldering repair. It's doable. But those little suckers are tiny. A hot air station and flux will be your best friends. [br]
[br]
[image|2716037]
[image|2716039]