820-3476-a Trackpad doesnt move

[macfix]

Hello Everyboady


I m working on A1502 820-3476 board its liquid damaged around keyboard. Track pad not moving ( click but not move)

- Tried knows good track pad and flex
- Checked connectors for any corrosion
- Checked PP3V3_TPAD_CONN and PP5V_S4_CUMULUS its ok ( also replaced r4808 and L4807)
- When i didnt connect trackpad fan spins high and other sensor problems but connected working without problem machine so trackpad connecting with machine...

I cant find 18V Boost connection to trackpad at this model where can i check?

 

[dukefawks]

Connect a flat cable and measure all pins that connect to U4801 from the end of the cable. Could be corroded track or pin.