7410 is generally a drum installation error. Did you recently remove or replace the drum unit? If so it is probably just not sitting correctly -- take it out and put it carefully back in again.
Otherwise the problem could be a bad signal coming from one of the circuit boards, or it could be a bad drum unit. You could try replacing the drum unit, but that may or may not fix the problem.
Answers & Comments
7410 is generally a drum installation error. Did you recently remove or replace the drum unit? If so it is probably just not sitting correctly -- take it out and put it carefully back in again.
Otherwise the problem could be a bad signal coming from one of the circuit boards, or it could be a bad drum unit. You could try replacing the drum unit, but that may or may not fix the problem.