Thanks for the props guys!
@chuck careful, don't stroke me too much. I might start labeling my threads in the 3rd person
. Seriously, thanks for the kind words. I don't start a thread every time that I fart in the hobby, but there are some things that I recognize that aren't very well documented that need to be seen. I like sharing this odd stuff.
One collectors trash is my treasure. My days were in the early 80's, but lets get real, most of that stuff can be done on a couple well done multi cabs. I've fallen in love with the odd, rare, cheap, dead junk of the 70's that no one gives a crap about. I have no formal training in electronics, but have gotten good over the years with my various hobbies with just staring at a schematic and reading up on stuff. A lot of that paid of with the gamble of the Star Shooter pinball I got recently
http://forum.arcadecontrols.com/index.php/topic,147394.0.html. There's also a certain rush to buying something broken for super cheap, complete, original, in good condition and to get it working again.
There is virtually no documentation on Table Tennis. All my search wordings for a manual or schematic led to nothing. I had never worked on anything EM before and wasn't really sure how far I would actually get with getting this thing working. The hardest part was figuring out how the 4 conductors going to the coin got connected. The coin box has ground, lock out coil, reset/start button and coin switch. There was no evidence of connection colors left in the box.
So that turned into plucking around with my meter and reading all the little strips that call out what each relay does. Once I had the proper coin box connections the relays clicked into action upon coin up and triggered power to the motors that led to a loud hum (quickly pull the f'ing plug!!!!). Between the awful to non existent motor mounts and the 44yo grease still on all parts, nothing was moving. I started with disconnecting the motors connection to the main shaft on each unit, coined up and the motors turned under their own power. Once that happened I at least knew all the motors still worked, it turned into pulling everything that was part of both motor units for a complete detailing/gegreasing/inspection. I learned a ton about the actual operation of the machine (which is f'ing fascinating) in the process.
Unlike most EM stuff both motors in this game are constantly turning during game play and specific reels are allowed to turn with the release of a solenoid at certain states of the game. I'll brush over what I learned about this thing.
A: is a 12v dc motor that is what I call the "cpu" of the game. A1: is the game code reel and ball animation reel. A2 is the paddle animation reel. A3: is a board that controls the speed of the ball and paddle motor which is randomized by the "speed advance index" relay.
B: Control motor, that handles credit accounting and scoring. It is made up of 2 brush less ac motors that are mounted face to face but reversed. Only one motor is used at the specific time and the other is just along for the ride. Each motor spins in a specific direction, 1 for resetting score reels and the other for adding credits and scoring. B1: Since the motors constantly turn the main shaft at all times, there are a number of "slip clutches" in each unit. It was all those plates springs and washers that I needed to keep a handle on when detailing (there are no parts explosion diagrams for this thing).
C: Is part of the wireless operation that originally came with the game and is not used. Small board is power supply for larger 2ch remote board. It was a factory option to have wired or wireless remotes. Obviously the wired operation is much better for game play eliminating the delay of old ass rf tech. C2: calls out the areas where the original wired remotes would have been installed for each player. C3 was for the armored cable going to coin box. The gray cable that mine came with has 8 conductors and was use for coin box and controls. I utilized it, but shortened / cleaned it all up and added a molex connector inside the main unit that connects to the coin box.
Just an absolute marvelous piece of historical hardware I'm proud to have fixed and play.
good day.