Hello, this MacBook is acting strangely. USB-C and Magsafe are able to get 20V for about a second, before the board crashes and it renegotiates. This is done on an infinite loop. i found evidence of liquid damage, namely some corroded components and some trails on the board. Notably, the SPMU (U7700) had a sticky looking circle on top of it, might be related might not. 3 of the inductors around it had dark brown spots on top of them. I replaced them and the corroded components but got nowhere. PPBUS_AON is not shorted to ground and I can't seem to find shorts anywhere else. I did notice a brown spot on the WiFi IC, but it came off with alcohol so I'm inclined to believe that was from the physical spill, and not from the WiFi IC shorting out and getting hot. There is otherwise no corrosion in that area as well. NAND's are also good, and under the backplate is completely clean. All replacements came from a donor board. Here's what I've replaced:
RP850 (PPLUXE_INPUT_R_V csense) - corrosion
QP800 (Connected to RP850) - corrosion
R6030 (20K sitting between P3V8AON_ISNS1_P and U6070) - Original corroded off the board completely, it came right off with no heat. Trace repair was not needed.
Reflowed U6070, not replaced - Was potentially lightly corroded, though hard to tell
L7810, L7842, L7852 - See aforementioned dark spots above
Starting at 9V, all the way up to 12.8V (where I stopped), the board will constantly draw 0.005A. When prompting boot, it will sputter about before crashing to 0A, then 0.005A, then repeating the cycle. I was able to force it into DFU with MacVDMTool while it is attempting to boot. It does successfully boot into DFU, and Apple Configurator is able to see it. Attempting to restore will yield the same power loop as before, and eventually it will stop with the error "Gave up waiting for device to go from DFU state to DFU state". Out of curiosity, I tried forcing DFU again once the power cycling starts, and that just caused AC2 to hang indefinitely (tested for 30 minutes, progress bar did not move at all).
RP850 (PPLUXE_INPUT_R_V csense) - corrosion
QP800 (Connected to RP850) - corrosion
R6030 (20K sitting between P3V8AON_ISNS1_P and U6070) - Original corroded off the board completely, it came right off with no heat. Trace repair was not needed.
Reflowed U6070, not replaced - Was potentially lightly corroded, though hard to tell
L7810, L7842, L7852 - See aforementioned dark spots above
Starting at 9V, all the way up to 12.8V (where I stopped), the board will constantly draw 0.005A. When prompting boot, it will sputter about before crashing to 0A, then 0.005A, then repeating the cycle. I was able to force it into DFU with MacVDMTool while it is attempting to boot. It does successfully boot into DFU, and Apple Configurator is able to see it. Attempting to restore will yield the same power loop as before, and eventually it will stop with the error "Gave up waiting for device to go from DFU state to DFU state". Out of curiosity, I tried forcing DFU again once the power cycling starts, and that just caused AC2 to hang indefinitely (tested for 30 minutes, progress bar did not move at all).