While you are inside the scope, or at least put it on your to do list (along with a full recap of the power supply as well) might want to visually check all the MB2501 fast recovery rectifier diodes (17 in total) on the power supply board, and replace the ones with ZM or ZS marked on them as it is a well known problem that they get leaky over time and will cause problems. This is a very common failure scenario for the 2245/6/7A/52 scopes. I replaced them all in my 2247A with MUR160 diodes from Mouser (PN 821-MUR160).
