820-3437 - Probing SMC_RESET_L makes SMC reset

Sykulski

Member
I got this liquid damaged 820-3437.

History is minor liquid spill around U5110. Was not starting. After UC starts when plugin in power supply.

Now when I push pwr on keyboard it immediately resets smc (charger goes green and machine reboots). Also as soon as I put the test-probe on SMC_RESET_L it initiates the smc reset (goes green and reboots). SMC_RESET_L is 3.12V

I changed U5110 and R5100 but still the same issue.

What to do now ?
 

dukefawks

Administrator
Usually trackpad or cable/connector issue. Pin 18 on J4800 is SMC reset line combined with the power switch. I say probably corrosion on the cable/connector/trackpad. In a rare case it could be the keyboard but then the left CRTL,ALT,SHIFT would also not function.
 

Sykulski

Member
Thanks Duke.

But with board out and keyboard connector removed it stills resets the smc when probing SMC_RESET_L.

Why?
 

dukefawks

Administrator
Cause your multimeter is loading it down. Is this an el cheapo meter? But has nothing to do with the trackpad/keyboard issue.
 
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