I love my Komatsu excavator but when I got it the thumb wasn’t working. I am not sure if I have a joystick problem or a solenoid issue. Everything appears to be plumbed properly. Any ideas where to start or which solenoid would control flow to the thumb? Also which buttons on the joystick control the thumb?
Have you enabled "attachment? "
When you press "Work Mode" switch on touch pad do you see option to select "ATT" attachment working mode?