A2179 MacBook Air 820-01958-A (2020) with SMC error

sekidata

Member
This 2020 Air came in with a liquid-damaged trackpad & cable, which I replaced. It starts up and works normally but AHT brings up the error PFM006 ("There may be an issue with the SMC").

I know the SMC is integrated into the T2 on these models, so I performed a DFU Restore, which did not change the situation. I also tried a different battery (no change). I tried unplugging the trackpad/keyboard before running AHT (no change).
 

2informaticos

Administrator
Staff member
The problem is not the SMC, but some thermal sensor.
PFM006 is usually related with trackpad sensors.

Be sure to get correct levels for 3V3/5V_G3S voltages at J6700.
Inspect j6700 for corrosion and check the solders.
Also check Q6861 and related resistors (page 54).
Be sure to get good trackpad flex; do not trust too much new chinese flex.
 

sekidata

Member
You were absolutely right. When I replaced the trackpad again, the SMC error disappeared. Turns out the initial replacement trackpad was bad.
 
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