[SOLVED]820-3115 No Trackpad, Keyboard works.

[SMMRepair]

Have an 820-3115 that's stumping me. Trackpad movement does not work in EFI or OS, but click/activation function of trackpad works in both EFI and OS. Have tried 3 test units (that are all known-good), and same behavior in each.

- No liquid damage; perfectly clean board.
- Have checked all relevant resistors on J5800/U5701 circuit, all check out fine.
- Missing PP5V_S5_CUMULUS
- PP3V3_S4 is present
- Replaced U5701 and U2700 out of desperation (no change)
- USB_TPAD_N is missing at R5702; is this normal, though?

What continuity should I be checking from J5800 to U5701 for this particular behavior? I have a feeling PP5V_S5 cumulus is the issue here, but can't locate the cause for it missing.

Thanks for all help.

 

[aprendiz]

PP18V5_Z2?? Trackpad connected.....

 

[SMMRepair]

Thanks, Aprendiz; will check. Quick question--will PP18V5_Z2 be present if L5800 is "NO STUFF", i.e. this isn't a Z2 particular board? Aren't these boards "either" Z2 or "PSOC"? Or am I confusing this? Will check that now.

 

[aprendiz]

L5800 is not present, this is Z2 flex so it need 18.5V..

 

[SMMRepair]

Thanks, Aprendiz. Makes sense; PP18V5_Z2 missing; I checked vin for U5805 and it was present, so replaced U5805 and all is well. Thanks, Aprendiz! You guys can close this one.