Did you replace/reseat the 40 pin inter-connector between the CPU and Driver board?
Did you check the 40 male pins on the CPU board, and checked for cracked solder joints on both CPU and driver board?

A little more information needed...try to be as detailed as possible:

SW has two target banks....Neither one reset ever? Both reset sometimes? One or the other reset never or sometimes?

Pop bumpers....Five Pops....All go out at once? Some go out and others are on? Other GI lights go out or just the pops? Are the pops on GI or MPU driven lamps (I don't have a schematic for Stellar Wars)?

Could be any of these. Scanbe sockets, black PROM legs, battery corrosion, failing 40 pin interconnector… these are all very bad things on Williams system3-6 games

Okay, center target not resetting is most likely one of the three switches is not making consistently, so it doesn't know to reset all three. Change of ball automatically resets the bank no matter how many targets down. That's an easy one to fix.

If all the lights are going out on the pops, I'd be looking at the GI string. Check your schematics and see what else is on this GI string and if those lights go out. If only the pop lights are on it and ALL of them go out at once, then probably a header pin/connector. If only some pops go out, then a loose GI wire in the string somewhere.

Another possibility with the pop bumper lamps, are the sockets. The pop bumper socket bottom lamp contact may not be making a solid connection with the lamp. There are a couple of ways to deal with the problem, such as replacing the socket, using a hooked tool to adjust the contact or wedging a piece of rubber under the contact to hold it up against the bottom of the lamp (cut a slice out of a rubber ring.)