Hi Guys,
We have an Apple MacBook Pro A2141 that did not turn on. USB-C meter showed stuck at 5V could not switch to 20V. We opened the back cover and we saw very dusty PCB. Removed PCB and checked under the microscope for possible corrosion. parts near to power chips / USB-C - 4 of them, were dusty. We cleaned them and then used thermal camera to analyze the board to see if we can detect any shorted element on it. We found one shorted capacitor which got hot (C9588). Also we saw that U5620 has corrosions on legs(ISNS_PPBUS_MAIN_SSD0_P). We removed it, cleaned the area and put a working donor U5620 chip from the working PCB. We also removed U9580 to check the legs but everything was ok on this chip mechanically.
We powered the mainboard without connecting it to battery. The volt switched from 5V to 20V and stayed at 0.05amps. We put the board back to computer and the computer started to use amps, we believe it was charging and amps went to from 0.05 to 2.5-2.7. After charging finished, we came back the next day we see it 5V and is not charging. Pressing power button and voltage goes to 20v and charging starts. We do not hear any chip and we do not feel any warmness on CPU side. While checking L chips around the CPU such as L7420, L7211 we do not have voltage. Upon checking for PP3V3_G3H, we do not see any power/votlage as well.
I need your help in this situation to move forward and to troubleshoot the issue. Please advise what to check. Thank you. See attachments as well.
We have an Apple MacBook Pro A2141 that did not turn on. USB-C meter showed stuck at 5V could not switch to 20V. We opened the back cover and we saw very dusty PCB. Removed PCB and checked under the microscope for possible corrosion. parts near to power chips / USB-C - 4 of them, were dusty. We cleaned them and then used thermal camera to analyze the board to see if we can detect any shorted element on it. We found one shorted capacitor which got hot (C9588). Also we saw that U5620 has corrosions on legs(ISNS_PPBUS_MAIN_SSD0_P). We removed it, cleaned the area and put a working donor U5620 chip from the working PCB. We also removed U9580 to check the legs but everything was ok on this chip mechanically.
We powered the mainboard without connecting it to battery. The volt switched from 5V to 20V and stayed at 0.05amps. We put the board back to computer and the computer started to use amps, we believe it was charging and amps went to from 0.05 to 2.5-2.7. After charging finished, we came back the next day we see it 5V and is not charging. Pressing power button and voltage goes to 20v and charging starts. We do not hear any chip and we do not feel any warmness on CPU side. While checking L chips around the CPU such as L7420, L7211 we do not have voltage. Upon checking for PP3V3_G3H, we do not see any power/votlage as well.
I need your help in this situation to move forward and to troubleshoot the issue. Please advise what to check. Thank you. See attachments as well.
