3115 not boosting PPBUS_G3H to 12.6V SMC Swapathon

grmacs

Member
USing 85W charger, getting only 12.3V on PPBUS_G3H. NO light on charger adapter. Replaced DCIN adapter with many different. SYS_ONewire is low usually at .7V sometimes at 1.3V (diode check red to ground there is .6V). I checked trace from U6900 to SMC and .9 ohms resistance. I've swapped the SMC 3 times and reballed etc... Replaced U6900.

Board does not start with battery and trigger SMC_ONOFF either.
 
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2informaticos

Administrator
Staff member
Incorrect PPBUS_G3H, there is a communication problem between SMC and U7000.
Did you test disconnecting BIL?
Post voltage and diode mode to ground ay SCL/SDA lines of battery bus.
 

grmacs

Member
Scl/sda lines are 3 mV difference. Board is out of the Mac so no BIL connected. I’ll swap the U7000 and check continuity between it and SMC where relevant.
 

2informaticos

Administrator
Staff member
Swap why???

"diode mode to ground ay SCL/SDA lines"
You've said something about 3mV.
I supposed to be voltage.
Many tinmes I said do not post "V" for diode mode readings...
 

2informaticos

Administrator
Staff member
Diode mode values look good, but voltage?
If equal, then could be bad SMC, or U7000 (less probable).
Be sure R7000 is OK.
 

grmacs

Member
R7000 is good. Voltage at SDA/SCL charger only is 3.49V. I tried swapping U7000 just in case being I already tried the SMC at least 3 times with no change in results.
 

piernov

Moderator
Staff member
Would be very unusual but you should check components in Y5010 circuit and continuity across traces. Also confirm no short to ground on PP1V2_S5_SMC_VDDC.
 

2informaticos

Administrator
Staff member
Check voltages and signals for U4900 (2 OF 2) at page 45.

Do you get SMC_PM_G2_EN?
Possibly not, but you didn't correctly reply to a previous question.
You've been asked about 3V3_S5.
3V3_S5_SMC comes from 3V42_G3H, not from L7220.
 

grmacs

Member
I do not get SMC_PM_G2_EN. It is 0V. SO you're right I don't get 3v3_S5. I actually thought I had checked that before but Piernov asked for 3v3_S5_SMC specifically.

Doesn't appear to be a short there. I traded out the U7941 just in case. So if not the SMC then must be the trace from SMC to U7941?
 

2informaticos

Administrator
Staff member
"Check voltages and signals for U4900 (2 OF 2) at page 45."
???

Any oscillation at SMC_E/XTAL?
Post DC level at least.
 

grmacs

Member
DAH it was related to the a missing trace from Y5010 to R5010 AND a bad DCIN board. Now I'm getting 12.65V on PPBUS_G3H and fan spin. Thanks Guys!
 
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