820-01521 No brain

No-Clean

Member
Clean board looks brand new and no liquid damage to be found.

There is no USB activity and obviously no external or internal image.

Mac allows me to restore T2 but that did nothing.

CPU gets hot and after a while fan spins, when charger is connected I hear chime for charging.

PP5V_G3S = 5.12 volts
PPBUS_HS_CPU = 12.64 volts
CPUCORE_PHASE1 = 0 volts
CPUCORE_PHASE2 = 0 volts
CPUGT_PHASE2 = 0 volts
CPUGT_PHASE1 = 0 volts
PVCCIO_PHASE = 0.97 volts
CPUSA_SW_LL = 1.03 volts
 

No-Clean

Member
Don't have good board on this one, if anyone has measurements that will be great, but sounds like dead CPU
 

No-Clean

Member
I should be getting one of this boards in shortly, the coils you mention are L7410, L8102, L7430, L7210, L7230 and L7290 correct? Did I missed or added to many?
 

2informaticos

Administrator
Staff member
CPUCORE and CPUGT...

But is good to make a list for each board model, when you finish the repair, with more test points.
This way you can build personal database, for future help.
 

No-Clean

Member
Ok I got a working board and here are the comparisons measured in Ω:

CPUCORE good board 12.5
CPUCORE bad board 8.8

CPUGT good board 9.2
CPUGT bad board 4.4

Should I look elsewhere for why this board doesn't start or is this CPU dead?
 
Top