820-3115-B Not charging & intermittent magsafe light

[ViBe]

MacBook 820-3115-B with prior repair came in for battery not charging. MagSafe takes a few seconds after power-on to light green, never changes to amber, and intermittently turns off altogether.

PPBUS_G3H is a steady 12.29V with no battery attached.
U7000 was replaced. No change.
U7000 resistance on pins 17/18 is 3.2 Ohms and pins 27/28 is 20 Ohms.
R7005 resistance is 20 Ohms.
Steady CHGR_ACOK signal, even when MagSafe is not lit.
Q7030/35 both replaced. No change.
R5280 and R5281 resistance both measure 2 kOhms.
On SMC_DCIN_VSENSE; R5498 resistance 27.3 kOhms, R5499 is 5.49 kOhms.
On SMC_PBUS_VSENSE; R5488 resistance 23.3 kOhms, R5489 is 5.47 kOhms. C5489 not shorted.

Any help would be greatly appreciated.

*Update: Booted the machine and appears that it doesn't see the battery. R7051 measures 2.5 Ohms, R7052 is 0.4 Ohms.

 

[2informaticos]

Incorrect communication between SMC and U7000.
Did you test disconnecting BIL?

Post voltage and diode mode to ground at SCL/SDA lines.

 

[ViBe]

Yeah, that's what I was thinking.

BIL disconnected.
Voltage on SDA is 3.034v, SCL is 3.477.
Diode mode on SDA is .520, SCL is .527.

 

[2informaticos]

Both lines should have the same voltage.
Diode mode difference should also be lower.

Possibly SMC problems.
Post U6900/01 voltages.

 

[ViBe]

Using a different adapter, magsafe light stays steady green but still does not charge.

U6900
Pin 1 - 3.475v
Pin 4 - 3.453v
Pin 5 - 3.453v

U6901
Pin 1/2 - Jumps from 3.267v up to 3.349v
Pin 4 - 3.476v
Pin 5 - 3.476v

Odd signal from U7000 considering that it was replaced...

 

[2informaticos]

U6900/01 both good, if get steady green light.
Which is actual PPBUS_G3H voltage (without battery)?

 

[ViBe]

PPBUS_G3H is still at 12.27v. I'm guessing communication with the SMC isn't right.

 

[2informaticos]

Remove C6952/53 (if present) and check again.
If still the same issue, change U7000.
Be sure first R7000 is good.
Last option, change SMC...

 

[ViBe]

Removed C6952 & C6953, no change. Still seeing voltage fluctuation from U7000. I'll change it again in the AM. Thanks, 2info.

 

[ViBe]

R7000 is good. Changed U7000 and now have no PPBUS. I'm suspecting that I may have a skunk set of ISL6259's, so I've ordered from a different supplier and waiting for their arrival.

Edit: Swapped the previous U7000 back in and still no PPBUS, so I may have mishandled it or created another problem.

 

[2informaticos]

Post U7000 basic voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.