Macbook A1990 820-01041 no power after pouring coffee.

ipetro

Member
The behavior and power supply on all ports are the same:
5.104V
0.053A

PPBUS_G3H=12.31v
PP3V3_G3H_T=3.37v
PP3V3_G3H_RTC_X=3.38v
 
Last edited:

2informaticos

Administrator
Staff member
Don't bother to check the same power rail on 5 points.
Do you really expect to get different reading?
Unless broken trace...

Check diode mode to ground on all secondary power supplies; big coils and page 79 outputs.
Compare with good board, or reference table.
 

ipetro

Member
I apologize if I write incorrectly or too much!

https://openboarddata.org/ I always start my work with this resource.
I did not find any deviations in the coils.
Fundemental power off checks: сс1 and сс2 are approximately the same 0.550.
Chip voltages: around the chips are also all working and present. on all four chips all readings are the same and work normally.
Boot sequence:
PBUS=ok
PP3V3_G3H_RTC=ok
PP3V3_G3H=ok
VIN_RTC > VIN_RTC_UPPER_THRESHOLD
this section has all voltages
H9M LOAD SECURE ROM, SMC BATTERY TRAP
this section is not working.
 

ipetro

Member
Yes, he is in DFU, but I didn’t do anything to make sure that it was safe! Is it possible to do a restore if the battery is low?
 

2informaticos

Administrator
Staff member
Some boards can complete DFU without battery, other no.
Restore will erase SSD, but data may be lost anyway.
Just in case, try revive first.
 
Top