[SOLVED]820-3115 9V on SMC_LID

Status
Not open for further replies.

jadao

Member
Water damaged near SMC. This one had no backlight issue (no bklt boosting because no PWM signal) because of SMC_LID partially shorted to ground on SMC (only 1.24V).

Replaced the SMC and now it works but SMC_LID is 9V!

Tried a reflow and made sure the smc "dance trick" but nothing change, still 9V, i am confident with soldering.

Backlight now works because hell SMC_LID is high now... did'nt tried yet if smc_lid come back low when lid is closed...

SMC seems alive, charging battery with orange light and ASD EFI report no errors.
I must admit this particular SMC came from china...

Have you had something similar? Any thoughts before i replace smc from a donour board.

Thanks
 

dukefawks

Administrator
There is no voltage higher than 3v3 around the SMC so impossible for this problem to come from the SMC. More likely is a short/leak in the board. Check if SMC_LID goes low when lid closed.
 

jadao

Member
You are right internal short.

SMC_lid goes low to 0.124V when lid is closed... Seems to work normally but for how long :(

Unfortunately I don't see any tracks at Q5701, R6961 and R5071 smc_lid goes right away through the board. It would be easy to recreate the circuit but the problem are the traces not accessible.
I thought maybe using pin 112 on smc and isolate USB_DEBUGPRT_EN_L it is adjacent to pin 111 but don't think worth the try.
 
Status
Not open for further replies.
Top