2 x MacBook Air A2337 820-02016 both working but no usb, no charging, shorts CD3217. 5.10v 0.2A draw.

[Emile Elfferich]

Hello everyone,
Used same charging cable. First A stopped recognizing my iPhone, then it stopped charging.
Please advise.

[mon2]

For the PD controllers @ UF400 & UF500, confirm the voltage to ground of:

PP3V3_UPC0_LDO
PP3V3_UPC1_LDO

[Emile Elfferich]

Thanks for your quick reply.
Enclosed confirmation voltages to ground.
+ same with other (yellow) multimeter.

[mon2]

On your Unit A - remove all power; measure the resistance to ground of PPBUS_AONSW_IPD. This is the power rail (after the load switch / e-Fuse @ UC850) that powers the trackpad. If this resistance is low, then disconnect the trackpad and test the resistance again. It is possible that UC850 is defective from some transient linked to the trackpad and this is forcing the upstream power rail PPBUS_AON to sink.

[Emile Elfferich]

PPBUS_AONSW_IPD = 4.62Ω at LT400 (1). Could not find spot on DC850 to put pin.
All 3 logic-boards are out out of the case, only USB ports connected.