as i said, rebuild kit first and if they are still popping fuses replace diodes, if still popping fuses then replace the coil, if still weak replace the coil. 

I started repairing pins back in 1987 and did it as a full time job for several years.
back then if the flipper was weak we would just replace the lot (coil, sleave, linkage, plunger, spring, eos,) it was more ecenomical to do this than have a pin with week flippers.
Once a pin was known to have week flippers by the regulars who played them the pin would take in a lot less money, once this happend the pin would have to be moved to a different site to start making decent money again. so it was just easier to repair it properly.