I am not happy with Your description of the problem - from post-1 I read "did run for some time - then a severe problem showed up" --- what actually is "stuck on Tilt" ?
Here http://www.stevechannel.com/tiltmechanism.htm is a good article - look at the last picture - usually the plumb bob tilt is mounted near the ball roll tilt. In Your pin the ball should stay in same position as shown in the picture. Do You see in Your pin such an "brass plate" as shown in the picture ? Maybe an preowner had unhooked and taken out the plumb bob Tilt ? Write about "brass plate" in Your pin.
Your pin is an rather modern Gottlieb --- it has not an Control Bank - it has an Coin-Unit (how many players want to participate in the next play) and it has the "not loved" AX- etc. Interlock-Relays. A picture of an Control-Bank: http://www.ipdb.org/showpic.pl?id=823&picno=19015 and a picture of Your pin: http://www.ipdb.org/showpic.pl?id=2539&picno=43468
"Control-Bank or no Control-Bank" - Gottlieb pins are built "strange - irritating" - we plug-in the main power cord and toggle on the main power switch --- we do see the "Tilt-Light" in the backglass lighted and we have no playfield lights lit (and we cannot move the flipperbats as there is not yet a game started). This situation*** we see I would NOT call TILT --- when we press the Replay-Button and nothing-happens*** - I would not call this "stuck on Tilt".
situation***: I call this "plugged-in,toggled-on - NOT YET a game started"
nothing-happens***: I call this "cannot start a game after toggling-on"
I show snippets of the schematics - I put colored numbers into the JPG (for easyer orientation). To start troubleshooting:
Look at the Q-Game-Over-Relay when You toggle-on the pin - does it pulls-in and stay pulling ?
Look at the U-1st-Ball-Relay when You toggle-on the pin - does it pulls-in and stay pulling ?
IF (if, if) they both are steady pulling: Wear rubber gloves or use an wooden stick (Safety Reasons, electricity can kill You) --- press the armature of the "H-Tilt-Hold-Relay" - does it stay pulling and the "Tilt-Light in the backglass turns-off" ? Press the armature of the " R-Hold-Relay" - does it stay pulling ? Press the armature of the S-Start-Relay - does it stays pulling for a while and the Score-Motor starts to run ? --- WHAT happens ? Greetings Rolf
P.S.: You may try the "pressing the armature" on Q-Relay and on U-Relay --- both must stay pulling --- we have trouble starting a new game if these two relays are not constantly pulling.