A2141 820-01700

[ipetro]

the macbook does not turn on! only the touchpad clicks!
not in dfu. caps lock does not light up. the behavior of the usb-c ports is abnormal!
with the battery connected, the usb-c ports on the j3300 = 20v / 0.000a both! the ports on the jb500 behave differently; the upper one (closer to the display) 5v / 0.100 (cyclically turns off), the lower one does not work!
if you disconnect the battery, the ports on the j3300 consume 20v / 0.112a both. the ports that are on the jb500 both work the same 5v / 0.300a stably! the battery is charged and works correctly with another board!
since I thought about the cd3217, I replaced all 4 from a working board (before replacing everything, I signed everything so I did not mix up), but the result is unchanged, the behavior has not changed!
short circuits were not detected, all base voltages are present!
NEED HELP

 

[2informaticos]

Do you have S-UEM2 tool?
You should compare diode mode readings between J3300 and JB500.

Consider to replace U2890 and UB090.
Don't forget to mark them first.

 

[ipetro]

unfortunately no S-UEM2!
after replacing UB090 all 4 ports work the same 20v/0.078a without battery and with battery 5v/0.000-0.028a. macbook does not boot

 

[ipetro]

and also when connected without a battery, the board starts with 20v/0.320 then immediately the indicator drops to 20v/0.0078

 

[2informaticos]

What is PPBUS_G3H voltage without battery?
Using 96W charger for sure?

 

[ipetro]

PPBUS_G3H=12.66V
I use the original 96W block and a 100W Bluetty station

 

[2informaticos]

Still not detected in DFU?

 

[ipetro]

Still not detected in DFU?

unfortunately no

 

[2informaticos]

Check required SLPS2R and AWAKE voltages, around U7800.

 

[ipetro]

all SLPS2R are present and correspond to the values of 1.1/1.8v etc.,
AWAKE are also all present!
T2 is barely warm on the thermal imager

 

[2informaticos]

Use external switch method to force DFU.

 

[ipetro]

I've already tried it, it doesn't work!

 

[2informaticos]

You may have problems with CD3217 chip related with DFU channel.

 

[ipetro]

I'm more inclined to think that the problem is in T2! Because I also thought that the problem was in 3217 and replaced all 4 with a fully functional blocked board! That is, neither the original nor the replaced 3217 can work correctly but at the same time have problems with the DFU lines! Or perhaps the problem is in the SSD (I don't understand how to check! Where to start

 

[2informaticos]

SDD can cause DFU failure; can't impide the machine to enter DFU.
Remember, many times SSD voltages are recovered in DFU.

 

[ipetro]

the fact that bad ssds do not prevent entering dfu is important information! thanks. in this case, the option of a bad t2 remains?

 

[2informaticos]

Check SOC_DFU_STATUS signal.

Be aware, sometime is really difficult to enter DFU.
I recommend to disconnect touch ID and solder another switch on the PMU_ONOFF_L too.
Playing with both switches should help you.