820-3115 no green led, no boot

[raainxx]

Hi,
i have this board 820-3115 with no green led.
I check this voltage:
PPDCIN_G3H=16,53V
PPVIN_G3H_P3V42G3H=16,13V
PP3V42_G3H_REG=3,495V (each side of L6995)
PPBUS_G3H=12,6V
P18V5_DCIN_CONN_R=16,41V
SMC_BC_ACOK=3,35V
what can i check more?
thanks

 

[raainxx]

i add more informations: no liquid, I use a power supply instead of magsafe board (16,5V display 0,02A)

 

[dukefawks]

Bad magsafe board? Does this board power on from a charged battery?

 

[raainxx]

No the magsafe board is good, and the board don't boot with battery charged and pad power on.
Do you have an idea duke?

 

[aprendiz]

Voltage on pins 1, 4 and 5 from U6900 and on pin 5 from J6900??

 

[dukefawks]

I don't care about one-wire at the moment as it also does not power from a battery. SMC seems to be running as PPBUS is at 12.56V. What is voltage on SMC_ONOFF?

 

[raainxx]

Hi
U6900 1,4,5 = 3,349V
J6900 5= 3,349V, sorry but the green led is here with another magsafe board, the led blink no really fix, but J6900 pin 5 on scope is good. but the board no boot, no fan, no display.
SMC_ONOFF=3,349V
thanks for your help

 

[dukefawks]

So much for a good magsafe board......

Check R7005, R7021/22/51/52. You sure this does not power from a known working battery?

 

[raainxx]

Ok i confirm, i test with another good battery not start when i short the pad start.
R7005=22ohm
R7021=12,5
R7022=12,5
R7051=3,1
R7052=0,3

 

[dukefawks]

G2_EN present? PP3V3_S5 present?

 

[raainxx]

SMC_PM_G2_EN=0v Pin2 U7941
PP3V3_S5=0V pin 6 U7941 & R7951

 

[dukefawks]

Seems like the SMC to me.

 

[raainxx]

Can i take it on a donate board?

 

[dukefawks]

Take from identical donor.

 

[raainxx]

ok can you confirm me it's U4900? how do you do to reball the chipset? sorry for this question but i haven't skill about that.

 

[ALB-Repairs]

With a stencil, or by hand with a microscope and a bit of time.
There is SMC replacement videos on youtube for more information.

 

[raainxx]

ok i see the video with louis, i find the stencil. thanks i post the result when i do the replacement.

 

[raainxx]

Ok i change the SMC and now i have SMC_PM_G2_EN=3,35v Pin2 U7941
PP3V3_S5=0V always, don't boot again.

 

[aprendiz]

Voltage on pin 6 from U7200?? Resistance to ground on L7220 without power applied of course...

 

[Gurmon]

Have you checked for shorts on PP3v3_s5 rail ?

If none are present whats voltage on pin 5 Q7221 ?