Just when I think I know what I am doing reality sucker punches me. I have killed my Tunnel feature on my Bally Space Time. I would be grateful foe any help. Ok you can point and laugh if you like. I probably deserve it

I have been restoring/refurbishing/abusing a 1972 Bally Space Time. Before I began working on the pin, I did get it functioning 100 percent. So I know everything worked correctly before I messed with it.

I just recently finished the cabinet and back box and am now I am waiting on the playfield to cure post clear coating before repopulating it. In the mean time, I Installed all of the cabinet and back box components and then began testing what I could without the playfield. I believe I have everything functioning correctly expect the Tunnel Freature/Flash Motor.

From the Installations and Operation instruction, the Tunnel feature works per the following.
Tunnel Feature:
FEATURE OPERATION AND SCORING
The “flash motor” unit controls the tunnel flashing lites and tunnel scoring.
The flash motor unit is controlled by the “tunnel relay” which is energized
when a ball goes into the outhole, left or right (eject) hole and when the
ball hits either “start tunnel” target. The flash motor stops when ball goes
over shooter alley roll-over or whenever the “collect relay” is energized to
score tunnel scores. The flash motor also stops when the game is tilted or
completed.
Skill Shots: To register a high score when ball is in shooter alley, the
ball shooter should be released so ball will go over shooter alley roll-over
when “5000” score lite is lit, and the ball should be i with just the
right force to go into “collect tunnel” lane at top of playfield.

When I manually engage the outhole, right or left hole, a switch on the tunnel relay sparks and the pin powers off (fuses do not blow nor does a GFCI trip). This is the switch with two yellow wires and one end of a 3300 ohm resistor on one blade. The other blade of this switch has a orange/red wire and connect with the other end of the resistor. (See attached pre cleaning picture of switch).

I believe I have checked all of the switches on the tunnel, start tunnel, outhole, left &right relays. They all looked correct however, I did ohm they out to be sure.

I also double checked the all of the wiring of relays, Flash Motor, and relaxing coil by comparing them with pre abusing pictures. They all matched the original wiring.

I checked the resistor out of circuit and it was pretty bang on 3300 ohms.

All of the coils also checked ok.

I am not sure if this is useful or not but, when I took the sparking switch off circuit and manullay engaged the outhole, left&right holes the pin did not shut down and these relays seem to function as they should.

Attached is the schematics for your convenience.
I am not sure what to investigate next. If you have a suggestion, I would be very grateful.

Phil

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Bally_1972_Space_Time_Schematic_Diagram_continuous.pdf

Thank you for your response.

When the Tunnel Relay is engaged/ tripped the Lock Relay disengages/releases.

I will further investigate for shorts.

Phil

Mark, you da man!
I checked once again closely examining for shorts near the tunnel release coil. Visually it appeared OK. However one lug of the tunnel release coil was very very close to the coil bracket. I checked with a DMM and store enough the coil was shorting on the bracket.

Originally the coil was positioned with the lug pointing sideways. After disassembling there wasn’t enough wire the reach the original position. So I turned the coil with the lugs pointing up. I did not take into account the the bracket angled up. The reduced clearance resulted in a short. I applied some electrical tape and problem solved (see attached picture). I make it look a little nicer tomorrow.

Thanks again for sharing your knowledge and helping bring and keep these pins working.

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