overshoot
Member
Hello,
Working on another old MacBook, an A1707, which came for, another... (drumroll please) blown capacitor on the PPBus rail.
Prior to replacing the blown capacitor, I got 20V with 80mA but no PPBUS. Found the shorted cap, replaced it, same symptom however I am now getting PPBus at 12.5V.
I'm missing now PM_SLP_S4_L and PM_BATLOW_L is sitting at 0.8V.
It's being pulled down by either the SMC, the PCH or one of the 2 Thunderbolt controller.
I have already replaced the SMC and the ISL6259.
I am afraid I am dealing with a bad PCH.
This signal comes from PP3V3_S5 through a 10k resistor which then connects to the SMC, PCH, etc...
I've cut the trace to the PCH only and the PCH side is at 0.3V while the other side remains at 3.3V, in other words, the PCH is pulling down that signal.
Anything else I can try from your experience?
Working on another old MacBook, an A1707, which came for, another... (drumroll please) blown capacitor on the PPBus rail.
Prior to replacing the blown capacitor, I got 20V with 80mA but no PPBUS. Found the shorted cap, replaced it, same symptom however I am now getting PPBus at 12.5V.
I'm missing now PM_SLP_S4_L and PM_BATLOW_L is sitting at 0.8V.
It's being pulled down by either the SMC, the PCH or one of the 2 Thunderbolt controller.
I have already replaced the SMC and the ISL6259.
I am afraid I am dealing with a bad PCH.
This signal comes from PP3V3_S5 through a 10k resistor which then connects to the SMC, PCH, etc...
I've cut the trace to the PCH only and the PCH side is at 0.3V while the other side remains at 3.3V, in other words, the PCH is pulling down that signal.
Anything else I can try from your experience?