[SOLVED]820-3437 - Sometimes working - sometimes not


I got this MacBook Air 820-3437

Came in dead. Does not have S0 Enables. So i measure diode mode on pin4 on U8180 and it is low (around 0.065V). I injected voltage on PM_SLP_S3_BUF_L. But nothing gets hot and current draw is low (around 0.1A)

Computer is working if i force S0 state by bridging pin4+5 on U8180 but then of course doesn't sleep very well...

Any tips to find out what is causing the low voltage drop on PM_SLP_S3_BUF_L and P5VS0_EN?



That can only come from U8180, U3210, U7870, U7600, U8080. First remove R8185/87 and see if that solves the low resistance. If not the U3210 would be my first suspect and after that just start pulling the others.