820-2936-B

[Anterweb]

I got this 820-2936-B with coke spilled inside it,

After putting through the Ultrasonic it came out spotless , It seems to want to try and boot without battery connected ( Gets half way through loading bar and the reboots )

But if I connect a known good battery the magsafe goes off completely and I have to unplug and plug back in the magsafe to get it to work again,

I cant see anything obvious the board looks good under the scope. Any ideas?

 

[2informaticos]

"17/18 = 8.13k"
Fix that, don't touch Q7055.
Check R7051/52 and their traces.

 

[2informaticos]

What is the exact PPBUS_G3H voltage (without battery)?

 

[Anterweb]

SO I went to check this and a couple of weird things from last night,
PPBUS_G3H voltage (without battery) = .220v
PPBUS_G3H voltage (JUST battery) = 11.96v

Magsafe green light is real dim and it will now only boot up from battery alone and does nothing with magsafe connected,

Also noticed when checking voltages that U7000 or a component very close to it is getting VERY hot when magsafe is connected , finger on board in that area gets a burn!

But as i said still boots fine with battery alone.

 

[2informaticos]

Check diode mode to ground on U7000 pins.
Pay atention to pins 2, 19, 20, 27, 28.

 

[Anterweb]

2 = ol
19 =.014
20 =.011
27 =.501
28 = .500

 

[2informaticos]

Renive U7000 and check again pins 19 & 20.
If good, replace U7000.

 

[Anterweb]

Renive U7000

Renive?? Did you mean reflow? or Remove?

If so how should I be measuring 19/20 and what should I expect a good reading to be?

 

[2informaticos]

Sorry for misstyping; I meant remove.
If U7000 is the culprit, you shouldn't get such low values (0.011/14), after removing it.