Macbook Pro A1706 820-00923-05 Stuck At 5V 0.03A

[Steven Pieter]

hello everyone, let me ask, I have a macbook which is stuck at 5v and 0.03 A when tested with a usb tester. Previously I wanted to replace the screen on the device, but by accident I forgot to unplug the battery. This caused the MacBook to get stuck at 5v, previously I had replaced the CD3215 (U3100) IC because it was warm. After I replaced it the problem was still not resolved. Please guide. Thank you

[mon2]

Check the voltage to ground on a few areas:

SMBUS_SMC_5_G3_SDA @ J6951 ; must be ~3v42
SMBUS_SMC_5_G3_SCL @ J6951 ; must be ~3v42

- if either of the above are 0v or must lower than 3v42, check if the 3v42 rail is present - if yes, then most likely the TVS diode @ D6950 has triggered and is now shunting this required SMBUS pair of lines. Flux and remove D6950 off the board to remove this shorted component. Test again.

PPBUS_G3H @ F7000 (check both sides)
PPVIN_G3H_P3V3G3H @ D6902, pin 3
PP3V3_G3H @ R6915

Often, not having 20V is due to the ACE (power delivery) controllers that are onboard.

https://logi.wiki/index.php/CD3215_Bootup_Sequence

Also,

https://repair.wiki/w/MacBook_Pro_A1..._of_20V_repair

[Steven Pieter]

Thank you for replying this are the following results I got after analyzing the voltage

SMBUS_SMC_5_G3_SDA 3v27 not stable sometime jump to 3v41 and 2v66
SMBUS_SMC_5_G3_SCL 3v29 not stable jump to 3v41 and drop to 2v79

PPBUS_G3H F7000 both side 0v54 on pin 1 and 2
PPVIN_G3H_P3V3G3H 4v8 sometime jump to 4v9 and drop to 3v8
PP3V3_G3H both pin 1 and 2 have 3v42

[mon2]

Flux and remove the fuse at F7000.

Then power up again. Test the voltage to ground on each side of the removed fuse at the pcb pads.

Is the ppbus_g3h voltage on the producer (isl) side stable?

Remove all power. Meter in resistance mode. Measure the resistance to ground on the consumer (downstream) side of the removed fuse.

What is the resistance in ohms?

[Steven Pieter]

Thank you for replying one again

yes the voltage on ppbus_g3h is stable at 3v42
check the voltage on the fuse F7000 pin 2 0v29 and pin 1 0v042
after that i checked the resistance on each side of F7000 pin 2 have 5.86K and its not stable it keep jumping up sometime it reach 1.000K . Pin 1 have 0.642 milihohm and it have same condition like pin number 2 (not stable)

[mon2]

The voltage to power the board travels from the adapter through PPVIN_G3H_P3V3G3H, then the isl regulator will ether buck (lower) or boost the input voltage. Currently not doing either.

The PPVIN_G3H_P3V3G3H rail should be stable.

Are you using the official power adapter for this logo board? If not, do you have a 100w rated power adapter for usb c?

The replacement ace controller is under suspicion.

Review the CD3215 thread linked in the first reply. It is practical to study each step of the 20v selection process.

The cd3215 should not be hot but each ldo power rail must be present. If you have a voltage that is present and then dips to zero volts then repeats, this is power cycling.

From where was the cd3215 sourced? What is the full part number of the original and the replacement?

[Steven Pieter]

yes i do have the official power adaptor after some inspection i do notice the cd3215 ic on the left side board (UB400 & U3100) have missing PP1V1_UPC_XB_LDO_BMC on the current active port, and the usb tester keep boot looping on that side.

[mon2]

Ok - double check your soldering. If necessary - replace this controller. Be sure to replace with a compatible one. Do not throw out the original controller - in case we can reball it for future. This one (non-working) controller can halt your boot cycle.