Apple MacBook Pro 16-Inch 2019 - A2141 - stuck at 5V

[martyjelen]

Hello, I have this Macbook A2141. It stuck at 5V / 0,075A. I measured all 4 ports, all the same. PPBUS_G3H is present but only 12,3V. Should be 12,6V ? according to this article : https://repair.wiki/w/MacBook_Pro_A2...w_at_5V_repair

PP3v3_G3H_RTC_X is present - 3,3V

PP3v3_G3H_SOCPMU is present - 3,3V

What else should I check?

Thank you for your help.

[martyjelen]

PP2v5_NAND_SSD0 and PP2v5_NAND_SSD1 are missing.

[mon2]

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

Test the resistance to ground of these SSDx rails. Post the measurements.

[martyjelen]

Hello, mon2. Nice to see you.

Resistance to ground on PP2v5_NAND_SSD0 is 1,5MΩ (measured on C9587)
Resistance to ground on PP2v5_NAND_SSD1 is 0,6MΩ (measured on C9586)

btw, device is not detected in DFU when I plug it.

[mon2]

What is the voltage to ground of PP3V3_UPC_XB_LDO? Used to power the external flash @ U2890 which contains the firmware to enable the 20V for the power delivery.

[martyjelen]

PP3V3_UPC_XB_LDO is 3,38V

[mon2]

Measure the voltage to ground of:

I2C_PWR_SCL
I2C_PWR_SDA

Jumping ahead, there are 2 roms on the board that are important on bootup. The rom @ U2890 (used by the PD controllers for the 20v) and the T2 rom @ U4770.

The U2890 dump should be posted on this forum. If you have a programmer, consider to backup the original and reflash this target. Be aware of the VCC of each. U4770 is 1v8. The PD flash is 3v3.

[martyjelen]

I2C_PWR_SCL is 1,8V
I2C_PWR_SDA is 1,8V

I have U301 USBC ROM Programmer. Could it be used for this package?

[martyjelen]

But i don't have any experience with flashing ROM. Must check some informations about it.

[mon2]

https://www.youtube.com/watch?v=RFo6ODG4Y8w

Yes, this tool is only to be used with the rom @ U2890 location. This flash holds the firmware for the CD3217 controllers. Assuming that each controller is ok, may be worthwhile to reflash this known good firmware onto this memory device. The contents of the firmware are also posted in the forum but your tool is the same. Be aware of the pin #1 location on the board and this tool. Take pics before starting.

Perhaps the firmware is corrupt so worth an attempt to reflash.

[martyjelen]

Thank you. I must set somehow that AsProgrammer can communicate with my USB ROM assistant.

[mon2]

This hardware is essentially the CH341A so this video should work for you:

https://www.youtube.com/watch?v=VzeeZj4Vvu4

[martyjelen]

One of my PC USB port not working. I tried another and it works now. Sorry for that.
I reflash original ROM but still gets 5V.

[martyjelen]

I noticed that when I connect USB-C to J3330 now after 2 seconds voltage drops to 0V. This doesn't happen before. Maybe I damaged chip? 🤔

[mon2]

Measure the voltage to ground on:

PPVBUS_USBC_XA
PPVBUS_USBC_XB

[martyjelen]

edited

PPVBUS_USBC_XA - 0V
PPVBUS_USBC_XB - 5V

[mon2]

Now flip the cable connector by 180 degrees. Measure again.

[martyjelen]

Same

[mon2]

Remove all power. Meter in DIODE mode. Red meter probe, yes red to ground.

Black meter probe to the point to test.

Test the PPVBUS_USBC_XA pin in DIODE mode. What is the measurement?

Also test USBC_XB_CC1. What is the measurement?

No power to the board during these tests.

[martyjelen]

PPVBUS_USBC_XA - 0,171
USBC_XB_CC1 - 0,622