This star trek machine is one I service regularly. From the last time I looked at it the right flippers both lower and upper seem a little weak compared to the left one. All flippers were replaced a few years ago and are in great condition. I checked the fliptronic pcb and found C2 100uf 100 volt ,was never installed even though it was shown in the manual.its just a smoothing cap for the flipper high voltage but after fitting one the result was the same. Just then tried disconnecting the top flipper incase the power was low because of both needing to work at Same time. No difference,still weaker than the right one. Eos switches are all new and test ok. Only thing I can think of is the CPUs timing for the duration of the strong solenoid pulse is too short because if you block the flipper half way up it seems weak compared to. Right one. The hold coil is there and is strong enough on all flippers. I never noticed the flipper problem on this machine before and I have had to service it for many years. We can still get all the ramps even the Borg ship, but only on what feels like a lucky shot. Perhaps flip tonic flippers just don't feel as real as the old fashion ones. Would love to hear others opinion on this. Perhaps it's just me

Good idea,worth a shot. Just looked through records and found last service that the spinner switch was not working.That time
I checked and found the wires for it had been deliberately disconnected, connected them and spinner worked .though no more about it. Now this time. The fault report on dmd told to check spinner switch. F 5 I think. Did that and the spinner seemed to work properly in switch test mode..As we know stng uses that switch ,it's special and is on the same circuit as the 3 EOS switches. I wonder does the spinner switch upset cpu EOS signals and someone obviously disconnected spinner switch to hide/ fix , a fault. Just thought if this this morning as flipper problem was noticeable straight away during this service. Fault diagnosis never showed up the spinner fault before even thought it was always disconnected and I only repaired it last time. Now with it apperantly fixed, it shows up as a ,check switch. If it is sticking on instead of open while in the rest mode I'm thinking that could upset the cpu?
The service manual does not make clear the purpose of the EOS switches on fliptronics as it works ok even when they are broken. They mention something about the feel of game and flippers lol. I may have to call again , the owner probably has not noticed the flipper issue yet?