sangolossyfon
New member
Have a pro 2012, board 820-3115. No boot or sign of life except the green charger light. No visible board damage.
G3H shows 13V and PP5V_S5 shows 5.3V, when board plugged in. PP3V3_S5 shows 3.47V.
However, the S3 and S0 lines are dead for 5V and 3.3V.
The only short I have found is a dead short on the PP5V_S3 line. It is a dead short, however, it seemingly 'goes away' about 20 seconds after I unplug the board. So if I unplug the board and immediately measure, the capacitance measure shows 001, and it also shows this if I measure while the board is plugged in. However, after about 20 seconds, it slowly rises to 470, no longer a short. The 5V_S0, 3V3_S3, 3V3_S0 lines do not have any shorts even while the board is powered on.
The fact that it goes away makes it hard to pull capacitors off and test the line for a short one at a time. I don't want to power the board on without some capacitors for risk of causing further damage.
I don't have a ton of experience repairing boards but I've only seen shorts that are always present, even if the board has no power. I don't know why it is going away after about 20 seconds, capacitor shorts I have seen in the past don't go away like that. Thanks everyone for any help.
edit: just realized I have two identical boards with this exact same issue.
G3H shows 13V and PP5V_S5 shows 5.3V, when board plugged in. PP3V3_S5 shows 3.47V.
However, the S3 and S0 lines are dead for 5V and 3.3V.
The only short I have found is a dead short on the PP5V_S3 line. It is a dead short, however, it seemingly 'goes away' about 20 seconds after I unplug the board. So if I unplug the board and immediately measure, the capacitance measure shows 001, and it also shows this if I measure while the board is plugged in. However, after about 20 seconds, it slowly rises to 470, no longer a short. The 5V_S0, 3V3_S3, 3V3_S0 lines do not have any shorts even while the board is powered on.
The fact that it goes away makes it hard to pull capacitors off and test the line for a short one at a time. I don't want to power the board on without some capacitors for risk of causing further damage.
I don't have a ton of experience repairing boards but I've only seen shorts that are always present, even if the board has no power. I don't know why it is going away after about 20 seconds, capacitor shorts I have seen in the past don't go away like that. Thanks everyone for any help.
edit: just realized I have two identical boards with this exact same issue.