820-000165 - Missing PPVCC_S0_CPU

menatwork

New member
Hi Guys,

Basically i got most of the rails, except the PPVCC_S0_CPU.
Any hint from this point?

Here is some measurements:

PPBUS_G3H = 8.6V
pp3v3_s5 = 3.3
PP5V_S0 - 5V
S5_PWRGD = 3.35V
Smc_s5_pwrgd_vin = 3.3V
PP1V05_S0 = 1.05V
PP1V8_S3 = 1.7V
PP3V3_SUS = 3.3v
PP3V3_S0 = 3.32v
PPVCC_S0_CPU = 0v


Thank you
 

menatwork

New member
SYS_PWROK 3.3V
U1950 = ALL_SYS_PWRGD = 3.38V
DDRREG_PGOOD = 3.3V
L7430 = 1.2V
PP0V6_S0_DDRVTT - 0.59V

U7400
Pin 2 = 1.2V
Pin 12 = 5V
 

2informaticos

Administrator
Staff member
If SMC_DELAYED_PWRGD is high, VCORE should be present too; check it again.
Also check PLT_RESET_L and PLT_RST_BUF_L.
 

menatwork

New member
Looks clean. However, i replaced and i got the same measurements:

R1931 =
1 = 1.05V
2 = 0V

C1930 =
1 = 3.3V




U1930 =
Pin 1 = 3.3V
Pin 2 = 3.3V
Pin 6 = 3.3V
Pin 4 = 0V
 

2informaticos

Administrator
Staff member
Post diode mode to ground at CPU_VCCST_PWRGD.
Check J1800 area for corrosion; remove R1800.
Change U1930 again.

You can also try the board removing U1930.

CPU remains as the culprit in the end.
 
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