No you can test these on the board.
No, they are not that sensitive to dirt.
Quoted from Hapidance:
When I jumped pins 4 & 5 on the board and the cpu read the switch on the test.
Good, then the issue is the board. If you have 12 volts on pin 1 and 3, if it was me I would replace Q-1 and D-1 as they are only .50 cents for both and I have them on hand. You do what you feel comfortable with.