Quoted from Bdkorn:
I am buying my first pin and I was wondering is there a recommended method to fully test STTNG to ensure everything is working? It has been fully shopped (w/ neutral zone cliffy and LED's), is there anything I should make sure is done?
"fully shopped" is a bit of a dubious term. it means different things to different people. the first thing i would do is remove the glass, lift the playfield, and look at the subway. if it's dirty, the game has not been "fully shopped", and you will likely get opto problems cropping up periodically.
make sure you know exactly how the game is supposed to work (The Pinball Arcade version is good for this -- i mean, the ball physics are all messed up, but you can learn the rules and when things are and aren't supposed to happen). before agreeing to buy the game, play it for a good long time and make sure every switch is registering properly, and the game isn't doing anything funky. (note: the Delta Ramp shot is much harder to hit in real life)
you want to avoid the game if it resets unexpectedly at any point.
probably the most common problem is the game spitting out balls (usually from the left VUK) when it's not supposed to, resulting in an unscheduled multiball. bad solder or dirty optos are generally the cause.
also make note if there is a credit dot (ask if you don't know what this is) and go into the diagnostics to see what is causing the credit dot. if it is complaining about the Borg Lock switch, don't worry about it, that probably just means nobody has hit a ball up the delta ramp and into the back of the ship in the last 90 balls. (if a switch doesn't get hit for a very long time, the game starts to worry that that switch is broken). any other switch error you will probably want to take a closer look at -- remove the glass, investigate if it's registering properly.
definitely check the ramps for cracks. lift the playfield and inspect the subway for cracks. look for wear on the inlanes and near the Romulan's head on the playfield (that's where the ball usually hits when it's launched from the left cannon, which is the one that gets the most use).
check that the lights in the Borg ship work. check that you can "stage" the upper flipper correctly -- that is, press the right flipper button in halfway, and ONLY the lower flipper engages. push it in all the way, and both the lower and upper flipper engage.
make sure both cannons work. (sometimes on startup only one cannon will move -- that's ok, as long as they both work in game)
make sure the flippers have enough strength to make the alpha and beta ramps. the delta ramp is a very hard shot, and a lot of people tend to mistakenly blame their inability to make it on a weak flipper.