Hello! My STTNG has been a handful for me. My wife and I bought it as our first pin, as well as Batman Forever. Both beautiful examples of these pins. I can post my maintenance logs here, to give you an idea of what I'm doing. Keep in mind, we are playing STTNG a lot, which works out all the kinks. I don't think they previous owner played it a lot. Logs:
3/31/2016 Inspection: Tested ALL optos, all are good. All subway diverters move freely. All coils move freely. Connectors secured. Tie-back has not been done on this pinball machine, but solders are in great shape.
4/1/2016, Ordered from http://www.marcospecialties.com :
STAR TREK NEXT GEN (WMS) Alpha Guards RG-11 1 $19.95 $19.95
STAR TREK NEXT GEN (WMS) Ramp Alpha PR004 1 $124.00 $124.00 (got a $35 rebate because of scratch on the ramp)
4/27/2016: Tom Grobe (tech) checked the main board. Cap and bridge are not original and seem fine according to meter. Also, pins in the 12v connector have been replaced by Tom (the whole connector, actually). Same circuit as F116 that keeps blowing. Still blowing on cold-start. FIXED: The left lighted flipper board was being ground by the playfield metal, and was causing a short.
5/7/2016: Tom Grobe (tech) replaced the left launcher coil and sleeve. He also replaced the Borg ship diverter coil, sleeve and shaft (bottom left of under playfield). Both coil springs were also replaced. Tom also adjusted some LED lightbulbs and also adjusted the flippers.
Ordered: Star Trek the Next Generation increase ferengi jackpot plastic, 31-1803-10
Plus (Your order number is: MS633236):
03-7066 tubing coil
31-1803-10 ferengi plastic
OUT OF STOCK a-13270 armature assembly (Equivalent A-17767 according to marco specs)
03-7067 tubing coil
Battery remote mount - solderless RBM 2 $16.95 $33.90
Armature assembly - Williams cup - no hole A-17767 2 $7.95
Armature assembly ordered because they were rounded at the top on both launchers. This wastes energy. As it stands now, the left launcher still doesn't always load. Talked to Tom and it might be the bridge(and diodes) "leaking", which would explain why it loads at the start of a game, but doesn't always load as the game progresses. Cheap parts to replace on the board($8). That's the next job.
So this is an example of STTNG work. Perhaps this stuff is common maintenance on 1990s pins?