Macbook A2159 Board 820-01598-A wont boot

[2informaticos]

CPU core should drop to 0.6V aprox, when board boots; if stuck on 0.84V no good.
Compare diode mode readings on the other J5110's lines with good board.
T2 might suffered damage on the data lines connected to touchbar.

Check if DFU revive helps.
If no important data on its SSD, go for restore.

 

[PACh]

Thank you for your reply.
at the beginning very fast to 0.5*V then to 0.84V and stays there...
on a good board J5110 line diode mode: 0.551
bad board: 0.539

 

[PACh]

sorry I understod wrong, all pins measures:

3: 0.506
4: OL
5: 0.506
6: 0.456
9: 0.504
10: 0.457
11: 0.505
12: 0.455
15: 0.517
17: 0.516
18: 0.543
20: 0.543
21: 0.465
22: 0.543
23: 0.465

and those are very similar to a working board

 

[2informaticos]

What about DFU?
Did you replace J5110?

 

[PACh]

going to try DFU now

 

[PACh]

DFU didnt work, I did a restore it went thru and appeared a lockpad icon but still no boot, no green light on shift key, cpu still gets warm...

 

[2informaticos]

Still not sure if you've replaced J5110.

Test the board alone on the desk, nothing connected, apart of charger.
Just check the CPU core voltage.

 

[PACh]

j5110 not replaced, but is not doing short or anything as the pin´s readings are all good. not easy to find that connector.
will check CPu voltage

 

[PACh]

CPU voltages the same 0.844V but now the amperage increased to 0.60-0.64A before DFU was around 0.50-0.52A

 

[2informaticos]

At least remove J5110 and test again.

 

[PACh]

connector removed, still the same

 

[2informaticos]

Possibly bad CPU, or some damage caused to T2.

 

[PACh]

yes looks like