820 3476 no green light no PP3V42_G3H

[funtotos]

hello
820 3476 no dammage liquid
I dont have PP3V42_G3H on this board.
r7020 16.6v

i have short on u7090 pin 2
resistance pin 2 u7090 42.6 Ω

Can u guys try help me figure out?

Thank you

 

[Gurmon]

Voltage on pin 6 and Pin 8 on U7090.

Diodemode reading on L7095.

 

[funtotos]

pin 6 and Pin 8 on U7090. = 14.31v
Diodemode reading on L7095. = .027v

 

[Gurmon]

So its not a dead short. I doubt injecting 3V into this rail will find the fault, but you could try as a LAST resort. Its time to examine the board for corrosion,

Was this liquid damage ?

 

[funtotos]

board for corrosion on r7095, c7094 and l7095
no dammage liquid .
When i inject 3.4volt on pin 2 l7095 = smc burn

 

[Gurmon]

Well that's shitty luck then. You'll need a donor SMC.

 

[dukefawks]

First solve the issue why the SMC fried, check the 3V42 regulator for corrosion.

 

[funtotos]

ahh good news, where is 3v42 regulator ?

thanks

 

[aprendiz]

Realy?? What do you think is U7090??

 

[dukefawks]

The SMC is dead, it died for a reason. First fix the reason why it died, then replace the SMC.

 

[funtotos]

I replaced u7090,
smc bc acok 3.34v

u7090
pin1 1,238v
pin2 3.46v
pin3 7.23v
pin4 3.43v
pin8 14.61v
pin6 14.61

l7095
pin1 3.44v
pin2 3.39v

f7140 12.34v

smc reset l 3.35v

why i still have a short circuit on pin2 u7090?
still no green light

 

[dukefawks]

You have 3.46V on pin 2 of U7090....how can there be a short?

 

[funtotos]

i don't understand,
when a put black probe on ground and red probe = on l7095 pin 2 or u7090 pin 2 .
my multimeter beep!!! 42.5ohm

multimeter on diode mode on rails pp3v42_g3h = .026v

why he beep ?

thanks

 

[funtotos]

I know .
it's crazy
diode mode in both directions
I have 0.27v and when I plug in the magsafe, I have 3.39v on pp3v42 rails

thanks

 

[funtotos]

i need you

 

[jadao]

You are probably and simply still having a partial short somewhere on the line.
While you were replacing u7090 and smc (after removing old chip and before putting new one) did the short went away?
Is the new esmc still burning?

 

[funtotos]

thanks you Jadao
I just replace u7090 , not smc.
i always have short on pp3v42 but i find 3.39v ......i don't understand !!
you want me to make a video on youtube ?

with the camera thermal , the smc and u7090 heat = 86 Fahrenheit

thanks

 

[dukefawks]

SMC is shorted, replace it with one from identical donor board.