820 2879 B , Green light but don't turn on

[Noguinfor]

Good Morning,

Board 820 2879 B, i have a green light but don't turn on.. missing =PP5V_S3_REG .. have 0V, and no short to ground in same lane..

where should i look ?

cumps

 

[luk812]

check around U7201?

 

[Noguinfor]

SMC_PM_G2_EN = 3.4v

U7840 - P3V3S5_EN_L = 0v
- P0V9S5_EN = 3.4v

51125 VIN = 12.6v

 

[aprendiz]

Did you short R5014 or R5015??? Or press power button??

 

[Noguinfor]

Wow... Machine comes up ... Sorry for my experience .. thank you aprendiz

 

[Noguinfor]

but, i don't understand why the 3v always is not in board.. but ok ty

 

[Noguinfor]

machine turn on, but no image and common sound.. after 20 sec cooler spin very fast... bios problem ??

 

[aprendiz]

You have said:

missing =PP5V_S3_REG .. have 0V

not PP3V3_S5_REG

 

[Noguinfor]

i say that because i think normal value is 3.4.. but normal value is 0v correct?

 

[aprendiz]

measure for missing voltages, CPU voltage, MCP voltage.....

 

[Noguinfor]

Hi aprendiz,

Missing:
PPVCORE_S0_CPU = 0v
PPVCORE_S0_MCP = 0v

where i look ?

 

[dukefawks]

MCPCORES0_EN present? If yes check for a short on L7560 to GND. If not 0 Ohm then could be dead U7500 or something around it.

 

[Noguinfor]

yes, i have 16.3V and short to ground in l7560. =(

 

[dukefawks]

How low is resistance to GND on L7560, it is quite low normally.

 

[Noguinfor]

in Diode mode i have short to ground.. And the resistance i have 11 ohms

 

[Noguinfor]

Machine delivered to costumer.. tank you