If the playfield lights are turning off during the game, something is affecting the H relay coil. A switch on the T relay can cut power to the H relay coil. The T relay coil gets power from three NO (normally open) tilt switches. If one of these tilt switches intermittently closes, this will cut power to the H relay coil. Look for the three tilt switches that have a red/yellow wire and an orange/white/red wire. I think the three tilt switches would be the plumb bob tilt, the ball level tilt and a switch tilt on the bottom of the main cabinet OR on the underside of the playfield. All these tilt switches need to be open to play a game. Check to see if the switches are open and have enough gap between the switch contacts. Might be a vibration issue where a tilt switch will intermittently close during game play. For testing, maybe remove the plumb bob tilt and the take out the ball from the ball level tilt and see what happens when you play a game.

Is this the sequence of events: You power on the machine, you press the start button, the machine complete resets, the ball kicks to the shooter lane and then the machine tilts. Ball is returned to the outhole, game goes to ball 2, ball kicks to the shooter lane, and the machine tilts again.

You said you had temporarily disabled the T relay. With power off, you can disconnect one of the wires from T relay coil or insert a small piece of plastic between the coil and coil plate to prevent the coil from pulling in when energized. With the T relay completely disabled, and the playfield down ready to play a game, power on the machine and try to reset the game again and see what happens.

If the machine plays normally with the T relay disabled, one probable cause is a circuit fault in one of the three tilt switches, or there is a mis-adjusted switch on the T relay. Check the T relay switch with the red/black wire and white wire to see if the switch contact is clean and adjusted properly. That switch should be closed when the T relay coil is NOT energized.

Did you also check the switch on the T relay with the red/black wire and white wire?

With the jumper wire installed at the H relay coil, does the machine operate normally and can you play a complete game?

Everything can appear normal on the relay, but switches may be dirty and even if they're closed, may not be bridging power to another part of the circuit. Relay coil might be weak or damaged.

Without the jumper wire, you power up the machine, press the reset/start button, machine resets and ball kicks to the shooter lane, playfield lights turn off and the tilt light goes on in the backglass. At this point, go to the H relay and push it in. When you push in the H relay, does it remain energized when you release the relay?

Check the H relay switch with the red/white wire and white wire. Power off the machine and manually push in/release the H relay. Look at how the switches open and close. When the H relay is pushed in or energized, the switch in question should be closed. You'll need to make sure the H relay switch with the red/white wire and white wire is adjusted properly and cleaned. Clean the switch contacts with a Flexstone, paper fingernail file or business card. Sometimes you need to "scrub" the switch contacts to get them clean.

Another switch you need to look at is a bounce switch that comes right after the fuse block in the circuit. This bounce switch has a red/white wire and a red/green wire (might also be a red/brown wire) and it's a NC (normally closed) switch. Make sure this switch is clean and adjusted properly. Clean the switch contacts and then adjust the switch to a tightly closed position.

You'll need to test the whole circuit with a jumper wire. Connect one end of the jumper wire to the H relay coil lug with the white wire and keep it there for all of the tests.

Take the other end of the jumper wire and connect to the following switch lugs one at a time:

Test 1------

Bounce switch lug - red/white wire

Then test machine and try to play a game.

Test 2-----

H relay switch lug - red/white wire

Then test machine and try to play a game.

Test 3------

H relay switch lug - red/black wire

push in relay to see if it will stay energized

If it stays energized, go to test 4

Test 4------

T relay switch lug - red/black wire

Then test machine and try to play a game.

Test 5------

T relay switch lug - white wire

Then test machine and try to play a game.

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On each test, note what the machine does when the jumper wire is on one of the switches. This should tell us where the general area of circuit fault will be located.

Test 2 showed there's no power at the H relay switch lug with the red/white wire.

Next step is to disconnect the jumper wire from the H relay coil. Then connect one end of the jumper wire to the bounce switch lug with the red/white wire and the other end of the jumper wire to the H relay switch lug with the red/white wire. Power on the machine and push in the H relay. Does the H relay coil energize and stay energized? If yes, reset the machine and try to play a complete game.

I'd test out the machine by playing multiple games. Play the machine as a 1-player game and play it as a 2-player game. On some of the games, manually tilt the machine by pushing the tilt plumb bob. See if it will tilt and then advance to the next ball.

If the machine plays normally with the jumper wire in place, then that means there is a break in the circuit between the bounce switch and the H relay switch. The schematic shows there are no switches or connections between those two points. I would look at the visible parts of the red/white wire first at the ends of the circuit. Maybe it's a cold solder joint or the wire is kinked somewhere. If you don't find anything, then you'll have to trace the red/white wire by removing it from the wiring loom. This shouldn't be that difficult, since the wire should be running between the two points in the main cabinet.

I'm not a fan of wiring modifications, but you can just leave the jumper wire in place until you have time to trace the red/white wire. Or just connect/solder a new section of wire between the bounce switch and the H relay switch. Still hope you'll take the time to find the problem with the red/white wire, repair it and put back to its original condition. But, these temporary repairs will be good enough for now so you can troubleshoot other issues with the machine...

Please keep us updated. It's actually kind of rare for a circuit wire to fail, so it will be interesting to see what you find. There's multiple ways to find the break in the wire - visual inspection, drop voltage test, continuity check, etc. So, you should be able to find this wire fault pretty quickly... Enjoy the machine!

Yes, I think it would be the same issue if it tilted by itself. Might be an intermittent issue. We will find out when you find the problem with the red/white wire. Although, the H relay might have a weak coil, and when it heats up over time, it will have problems holding the relay in the energized position. I would still troubleshoot the red/white wire first, repair it, and then test the machine for any additional problems.