A1465 820-00164 no power

[hgoncalves]

Hi,

I have an A1465 820-00164 that has green light, but no fan spin, no usb activity, and no voltage on cpu coils, and puls 100mA from bench PSU.

It seams the Q8150 has already been replaced before. I get 0.100V on ALL_SYS_PWRGD.

Can you help?

 

[2informaticos]

Post some basic voltages from the MLB...

 

[hgoncalves]

Hi, Sorry...

PPBUS_G3H = 8.58V
PPBUS_S5_HS_COMPUTING_ISNS = 8.57V
PPBUS_S5_HS_OTHER_ISNS = 8.57V
PPDCIN_G3H_ISOL = 19.94V
PP3V42_G3H = 3.43V
PPVRTC_G3H = 3.34V
PP5V_S5 = 5.1V
PP5V_S4RS3 = 5.1V
PP5V_S0 = 5.1V
PP3V3_S5 = 3.3V
PP3V3_S4 = 3.3V
PP3V3_SUS = 3.3V
PP3V3_S3 = 3.3V
PP3V3_S0 = 3.3V
PP1V8_S3 = 1.79V
PP1V2_S3 = 1.2V
PP1V05_SUS = 1.06V
PP1V5_S0 = 1.5V
PP1V05_S0 = 1.03V
PPVCC_S0_CPU = 0V

 

[2informaticos]

ALL_SYS_PWRGD goes high?

 

[hgoncalves]

I get 0.100V on ALL_SYS_PWRGD.

 

[2informaticos]

Remove Q8150 and test again.

 

[hgoncalves]

W/O Q8150 i get 3.3V on ALL_SYS_PWRGD

 

[2informaticos]

CPU gets power now?
You can leave out Q8150.

 

[hgoncalves]

Yes it does, and now I have boot.

With other Q8150 it doesn't boot and i don't get ALL_SYS_PWRGD high. Is it safe to leave it out? No function gets lost?

 

[2informaticos]

Q8150 isn't the issue.
You have problem with one resistor divider from its inputs.
You can leave it as is; Q8150 is a redundant protection.

 

[hgoncalves]

OK. TKS!