820-00281-A 20v-1.05a

fixupp

New member
Hi, Im just start learning motherboard repair, please assist.
I have this board with no water damage and mint condition. Customer said it was suddently dying while working.
It takes 20v 1a with no battery or 20v 4a with battery connected. No chime, not turn on, trackpad clicks.
the board is getting very hot, specially CPU and PGU area, is it a bad CPU sign? customer needs the data
Follow the Apple Macbook T2 Platform startup sequence on repair.wiki and here are the readings,

PM_PCH_PWROK 3.3v

ISNS_CPUVDDQ_N: 0v

ISNS_CPUVDDQ_P: 0v

PM_PWRBTN_L: 3v3 not pulsing

ALL_SYS_PWRGD: 3.184v

PP1V0 - 1v, 1v2- 1v2, 1v8_S3: 1v8: S3 power rails seem to be good

PPVCCIO_S0_CPU: 0.95v

PPVCC_S0_CPU: 1.05v

PPVCCGT_CPU_PH1: 0v
PPVCORE_S0_GPU: 0.902v
 
Last edited:

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

Is the CPU core steady 1.05V after 10-15s?
PLT_RESET_L comes high?

You should try known good BIOS.

The data can be recovered with dedicated tool over Lifeboat connector (J9600), even if Intel side doesn't work.
 

fixupp

New member
Thanks for the reply.
Already tried with new bios but same issue.
PPVCC_S0_CPU stable at 1.05v after 20s

PLT_RST_L: at first 3.v3 then go low 0v in arround 6 secs then back to 3.3v
 
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