Did you look at the schematic and peak at the switch on the scoring motor that is in the path? That is one location you did not mention. All targets on the playfield score without sticking a relay? Coin switches ok even if switch closed on credit wheel for freeplay?

Look in the score motor diagram for switch 1-A.

hottip (resized).png

I have not had my nose in that game in some time but if it is like most Bally score motors as you're looking down into the cabinet at the score motor it should be the first row bottom switch. Not knowing the condition of your cabinet there should be a long strip of paper with printed numbers in the cabinet next to the score motor. 1 tells you what row the switch is in and the A tells you the level. Level A is closest to the cabinet floor with switch 1B above it. Look for bent tabs and clean & adjust if needed.

My Hot Tip (EM) has done that on occasions. If you have isolated that there is nothing wrong with the Ball Count Unit step-up mechanism, then there are basically 4 stand-alone switches to examine, plus the switching interface between the Player Unit and the Coin Unit steppers.

If the game is only failing to step up the Ball Count Unit on a specific ball (say ball 3, for example), then you can most probably concentrate on the interface between the Player Unit and the Coin Unit, as the other switches are not at all ball- dependent.

If the game randomly fails to step up the Ball Count Unit on various balls (1, 2, and/or 3), I would start first on the other 4 switches.

The Motor switch 1A that you have asked about is located at the lowest (A) level of the switch stack: the bottom switch closest to the #1 cam itself. The #1 cam is the 2nd cam in from the left side as you look into the cabinet from the front of the machine. It is hard to get a good look at. It may help to remove the left-side hold-down screws on the motor bracket and hinge it upward, so that it is oriented straight up & down. The switch should only be closed when the cam follower drops into one of the 2 notches on the #1 cam. At the very least, clean the contact and consider tightening the gap just a fraction with a contact adjusting tool.

Have fun. Hot Tip EM is a great game! Pretty close to Grand Prix, IMHO.

Lee

Added note: the last time my Hot Tip exhibited this behavior, it was always repeating ball 3 once or twice, so the player would get a 4- or 5-ball game before it went to game over. In my case, I went in and examined the Player Unit and Coin Unit switches for the ball 3 position. I found that the Player Unit (located in the head) snowshoes were slightly misaligned and were just barely hitting the edge of the rivets. I realigned the stationary board by rotating it and also used the opportunity to put a little more tension on the rotating spider arm of the Coin Unit. The game has been perfect ever since, so keeping my fingers crossed.

L

Thought of one other possibility. The circuit for the Ball Count Unit step up goes through a switching interface between the Player Unit and the Coin Unit, as can be seen in the schematic snippet that you posted. Since the Coin Unit is on the cabinet bottom board and the Payer Unit is inside the head, the signal must go through wiring harnesses and Jones plugs.

You might want to inspect the Jones plugs to make sure they are clean and there are no wires broken off the male and female connectors, either of which could impede the signal path.

Lee

Grrreat that you got it playing again. So, the culprit appears to have been motor switch 1A? That's a hard one to get a good look at and the back side, where the wires are located, is even more "congested". Hope you never have a wire break off behind the switch!

Hot Tip does not get a lot of love on this site, but I love the progressive drop target sequences with the increasing point scores, to first light the spinner, then the free ball hole, then the special and the 10,000-pt light. The spinner and the captive ball are a blast too. Fun game.

Lee