820-3115 SMC_PM_G2_EN 0V

brunomotter

Member
Hello. Got this board here. PPBUS_G3H is 12.23V, which means SMC is not talking to ISL. Replaced ISL and SMC but still same results. SMC_PM_G2_EN is not present. SMC_RESET_L is steady 3.3V. PP3V42_G3H is steady 3.42V. I get no green light on charger eve though ADAPTER_SENSE is steady 3.42V. Tried replacing magsafe board with known good one, still same. I'm stuck now. I'm sure this SMC chip I soldered is good because it was negotiating 12.56V on the donor board I took it from(donor board got bad PCH). What else can I check?
 

brunomotter

Member
Hello.

PP3V3_S5_SMC - 3.34V
PP3V3_S5_SMC_VDDA - 3.34V
SMC_WAKE_L - 3.34V
PP1V2_S5_SMC_VDDC - 1.2V
PP3V3_S5_AVREF_SMC - 3.3V

Replaced Y5010 just in case as I don't have oscilloscope to measure its clock signal. Same thing.
 

brunomotter

Member
There was a broken trace between R5010 and SMC. Ran a wire and now I get green light and 12.56V on PPBUS_G3H, but still no power. S4 rails are not activating.
 

2informaticos

Administrator
Staff member
For the future, if you cannot control the frequency with o-scope, or frequency meter, check DC voltage at crystal pins at least.
You will find 1-1.2V DC for working crystal, on both pins.
 
Just now i am working on 820-3115. Sus o/p signal from pch is missing. S5_PWRGD is getting generated but PM_RSMRST_L is missing. Tracing the signal i find PM_SLP_SUS_L is missing. What should i check in PCH. ?
 
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