graphite is powdered a carbon derivitive making it an excellent conductior of electricity.
it is good that you asked your question. on both repairs i left this step out.
just did not have any around, suppose soft pencil lead (graphite) could be used as well.
I cleaned the pcb and contact fingers with crc qd electronic cleaner very mild
solvent using a lint free paper towel. i also lightly bent the contact fingers down for better contact with the pcb.
getting the head out is not very involved. slpitting the control head to get at the pcb and fingers is a bit ticklish. you must patient and easy so as not to break any holdin tabs. small thin blade screwdrivers work well.
perhaps you can show this to someone who could assist you in the repair.
just make certain this is your problem and not something else.