820 3115 charging issues

[EJS]

820 3115 came in for no power, and had no light on mag safe. I replaced u7000, now I get a greenlight and the machine powers on and fully boots, but does not recognize or charge the battery, geenlight never turns Orange. PPBUS G3H is low @ 12.25v. PP3V42 is present.

 

[2informaticos]

First check if R7000 is OK.
Next check resistance to ground (diode mode, red probe to ground) on SCL/SDA lines of battery bus.

 

[JohnB8812]

Voltage on SMC_RESET_L? Any history of liquid damage possibly near the SMC or ISL?

 

[EJS]

Okay fellas, r7000 is .2ohms looks good. Resistance to ground is on SDA .475v, and .481 on SCL. I have 3.42v on SMC_RESET_L. This board is very clean, it doesn't look like liquid has ever touched it.

 

[2informaticos]

Did you disconnect BIL?
Post voltage for pins 9, 15, 26 of U7000.

 

[EJS]

Disconnect BIL? Im not sure I understand that part of your question 2info.
pin 9 0.028v
pin 15 0.039v
pin 26 16.27v

 

[2informaticos]

BIL connector, J6955.
Also post voltage on SCL/SDA lines.

 

[EJS]

Bil, was connected for the last few measurements I posted before.
scl 3.460v
sda 3.374v

 

[2informaticos]

Post again resistance to ground, without BIL...

 

[EJS]

SAD .482v
SCL .483v

 

[2informaticos]

Reflow SMC and check if detects battery.

 

[EJS]

I reflowed SMC, I am still getting only 12.25v on ppbus

 

[JohnB8812]

If that is without the BIL plugged in, then either bad ISL or bad SMC. I'd say try another ISL to be safe first as it is easier to replace for obvious reasons.