820-2915 reset charger and green light and fan spin but shutting charger off

[grmacs]

I did check out of case with nothing else connected. will do.

 

[grmacs]

NOw .522V SDA & .505 SCL
R5280/1 are both exactly 1.97K ohms

 

[2informaticos]

Try removing each component connected on these lines.
Remove ISL6259 before SMC; let it at the end.
C6952/53 and even corrosion under J6950/55 is possible.

 

[grmacs]

Went throuth those one by one and was always about .18V difference SCL/SDA voltage drop.
Had to replace SMC again. Solved the SCA/SDL issue. 12.62V PPBUS. No Fan spin.

 

[grmacs]

Power rails I've checked. I don't have much experience checking through power rails but referred to prior case where it applied:

S5_PWRGD is 3.4V


PM_SLP_S4_L is 0V


3V3_S5 =3.3V


SMC Adapter EN= 3.4V


PM_BATLOW _L= 0V


PM_DSW_PWRGD,= 0v


PCH_DSWVRMEN,= 3.24V


PM_RSMRST_L, = 0V


PM_PWRBTN_L = 3.4V

SMC came from another 2915 board and using 85W charger.

 

[2informaticos]

PM_BATLOW _L shoulf be high with 85W charger.
Check power charger reported in System Report from working machine.

Check if your board starts with both charger and battery connected.

 

[grmacs]

working machine recognizes charger as 85W. No start with battery and charger connected.

 

[2informaticos]

" S5_PWRGD is 3.4V
----------------------
PM_DSW_PWRGD,= 0v "
This could be SMC issue; check the Apple note ftom page 72.
Even PCH can pull down this signal; if has an internal damage.
Check all RTC signals at page 16.

 

[grmacs]

Reballed and did SMC again
SDL/SCA lines still good.
PM BATLOW L is still 0
PM DSW PWRGD still 0

SYSCLK_CLK32K_RTC = .4V
RTC_RESET L = 3.47V
PCH SRTCRST L = 3.47
PCH INTRUDER L = 3V
PCH INTVRMEN L = 3.35V

 

[2informaticos]

If S5_PWRGD is high, SMC MUST release PM_DS_PWRGD signal; did you read the note???

Try another SMC.

 

[grmacs]

YEs I read the note but wasn't sure if the RTC readings you requested were relevant to a bad PCH. I don't understand how the RTC signals are related to the diagnosing or if they would infer a damaged PCH as you also mentioned.

I'll try another SMC!

 

[2informaticos]

Old boards have 4 RTC DC signals for PCH.
PCH can start power on sequence without RTC clock, but NOT if one of the other 4 DC signals is not correct.
Nothe that, new PCH generations do not require PCH_INTVRMEN, nor PCH_INTRUDER_L signals.