MacBook Pro A2141 820-1700: Missing pp3v3_s5

[xenirox]

Hello,

I'm writing this Thread after searching all over the forum and the internet, i can't find a solution, so i need your help.

I have a friend's MacBook Pro A2141 board reference 820-1700, that is supposed to have condensation, because he have it in his backpack while it was raining.

It gets 20v and 0.065 amps on the usbc amp meter.

I have all voltages on SSD, no short on this rails.

PPG3hot is 12.6v.

When i test the boot sequence voltages the first that is missing is the pp3v3_s5 and the line is not shorted.

It boots up in DFU all the time, but i can't revive or restore it, it gave the error 6 message.

I need your help and expertise.

Thank you so much in advance !

[xenirox]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

I need you help please

[mon2]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

From logiwiki on DFU topic:

6 - Probably could not write BridgeOS into service partition. Most likely SSD failure. There might be one hot NAND. Common symptom - T2 does not turn on S5 rails at all. If you have it in revive mode, try restore (All data will be lost!).

Common symptom of Bad SSD volume is T2 tries SSD power resets every few seconds or up to 23 seconds.

[xenirox]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

Thank you mon2 for your help.

I’ve already checked logiwiki, but i have all SSD voltages that are supposed to be shorted to ground, but there is no short.
Under thermal camera, the T2 is getting a little hot, no more than 40 degrees celsius. But SSD are cold

What do tou think of replacing U7800 as last thing to try?

[xenirox]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

I’ve replaced the U7800, but same problem.
Any ideas to help me push further the investigations ?
How can i be sure that the NANDS are faulty ?

[xenirox]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

Help please ��

[mon2]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

Measure the voltage to ground of SOC_DFU_STATUS.

[xenirox]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

Measure the voltage to ground of SOC_DFU_STATUS.

1.8v with and without battery.
When the battery is plugged, it charges but very slowly, it goes up by 100mA if it can help identify the problem

[mon2]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

Based on this logic ‘1' at 1v8, you are in DFU mode.

See the section on logiwiki for ‘DFU error codes and troubleshooting' on ideas for a resolution.

Is the ssd power pulsing?

Is the trackpad attached?

[xenirox]

Re: MacBook Pro A2141 820-1700: Missing pp3v3_s5

Based on this logic ‘1' at 1v8, you are in DFU mode.

See the section on logiwiki for ‘DFU error codes and troubleshooting' on ideas for a resolution.

Is the ssd power pulsing?

Is the trackpad attached?

The trackpad is attached, and the SSD voltage is 2.5 and drops every 1min approximately.

I can be a defective NAND that is not shorted to ground ? If so how can i be sure ?
Thank you in advance