MacBook A2141 one USB port dead and one power cycling

[dbuergi]

Hi all,

I got a 16inch MacBook Pro showing 5v and 0,3a on the left ports and right side has one power cycling and one showing nothing. The one cycling shows 30c under thermal camera. Surrounding components show no corrosion or any shorts.
Any ideas what to check next? The whole board looks clean compared to the other A2141s i saw.

[mon2]

See attached. You are at the power sequence #1 stage.

Remove all power. What is the resistance to ground of PPDCIN_G3H? Issue is most likely with one or more of the CD3217 PD controllers.

[dbuergi]

See attached. You are at the power sequence #1 stage.

Remove all power. What is the resistance to ground of PPDCIN_G3H?

Resistance to ground is 955 Ohm.

[mon2]

This may be your case study:

https://repair.wiki/w/MacBook_Pro_A2...w_at_5V_repair

[dbuergi]

I replaced one cap and gave both CD3217 on the right side a reflow. Now all ports show 5V and 0,17A. Also no difference with battery connected so next step should be to try a DFU restore?

[dbuergi]

Sorry was not able to edit but i made a mistake. 3 Ports Show 5V and 0,2A and one 5V and 0,12A.
With battery connected three ports show 20V and the one stays at 5V and 0,12A. So still problems with the Cd3217 of this port?

[mon2]

Use the port that allows for 20v for now. What is the volt to ground on PPBUS_G3H?

[dbuergi]

Use the port that allows for 20v for now. What is the volt to ground on PPBUS_G3H?

12,3v and cycling to 11,6v and going back to 12,3 again.

[mon2]

Test the nand flash capacitor to see if it is shorted.

reference:
https://repair.wiki/w/MacBook_Pro_A2..._at_20V_repair

No power to the board when testing the resistance to ground.

[dbuergi]

Test the nand flash capacitor to see if it is shorted.

reference:
https://repair.wiki/w/MacBook_Pro_A2..._at_20V_repair

No power to the board when testing the resistance to ground.

Sorry was busy the last days. Cap and everything around is fine and somehow my 5v port is now dead again and all others show 5v.
The one marked with X isn't showing anything right now. I added values i got when connecting power to the other port.
Can this all be the problem of a faulty UB300 or do i have to look anywhere else?

[dbuergi]

I reballed UB300 to see if it changes anything and all values look fine besides CB308 being at 30 Ohm.
But testing was not possible. Port for UB300 still shows nothing with USB tester connected (dead) and port for UB400 just flashes for a second and turns of and on again in a loop. Never had the situation where the port was "dead" so any ideas what to check or can this also be the case when UB300 needs to be replaced?

[dbuergi]

So, i got a donor board and changed UB300. All ports work now but i only get 5,17V, 0,06A and 0,33W.
The port flashing was a faulty ISL9240 which i also replaced.

[mon2]

Test the voltage to ground of each LDO rail on the CD3217. Confirm the voltage on each pin of the SPI flash used by these PD controllers.

[dbuergi]

CB304 1,5V
CB300 3,4V

I took SPI flash out and got 0,90V on pin 5+6 and every other pin 3,3V besides pin 4 GND 0V. With SPI flash back on board i got 0,40v on 5+6 and all others showed 0V.
Also i took the ISL9240 out again since the pads looked strange under the microscope.

[mon2]

Meter in DIODE mode. Measure each pin on the flash device in diode mode. Red meter probe to ground. Black meter probe to the pin to test. It appears from your last post that this flash device is defective. Post each measurement.

[dbuergi]

Hello mon2,

Since nobody is sure if both CD3217 chips need to be changed i also changed the second and SPI flash chip from donor. Now i have:
P1 0,6V
P2 0,6V
P3 0,6V
P4 0V
P5 0,6V
P6 0,7V
P7 0,7V
P8 0,5V

Right now i saw that the ISL9240 has two strange looking pads under the microscope. I will also reball it again. Somehow the chip sucks off all head and it takes ages to solder it. Newer had this problem before. Maybe i should use a heating plate.

[mon2]

These are good diode mode measurements. Nothing appears to be shorted here. If you power up with this new flash device, what are the voltages to ground on each flash pin? Appears to be a better device than the original.

[dbuergi]

I get power cycling from 0,3V to 3,4v and USB tester ist flashing. This happends with soldered ISL9240 chip.
Checked everything again and i have a short to ground at C7080, so search goes on.

[mon2]

ISL soldering is good? What is the resistance to ground of C7080?

[dbuergi]

ISL soldering is good? What is the resistance to ground of C7080?

I reballed it two times and it moved in position.
C7080 shows 3,4 Ohm. Meassurements also stay this low with ISL and / or C7080 removed.
Also with the changed CD3217 removed again the line stays low. I tried some voltage injection and got 30C hot spots at T2 chip and U7800. Is there a chance that they cause this problem even 30C is not really concerning.