TokensArcade
Member
Chicago Coin TV Ping Pong (Atari Pong Clone) Restoration
Hello KLOV:
Just here to show a bit of a project I've been working on. I've worked on a fair few games in the past, but now I'm working on my first TTL game! A 1973 Chicago Coin TV Ping Pong. It's essentially one of many Pong Clones made back in the day. I scored this baby for a whopping $25, untested!
It's missing its coin door and it's plug was chopped off when I got it, but for this price, I couldn't say no! I have some experience with TTL stuff from my engineering classes in college, so I felt like I had a reasonable chance at fixing it. I took it to the shop and turned it on after replacing the power plug. TV came on, but nothing on screen and no sound. I couldn't get the coin counter to kick either. After confirming the power supply was working I found 0v at the board. Eventually I determined the board was shorting between 5v and ground and after removing the a leg off of various resistors and other small components (finding a bad diode in the process) from the board, I realized that it was one of the TTL chips causing the short.
It was this that finally pushed me to buy a proper Hakko desoldering gun. As I realized after removing one chip the old fashioned way, that this was going to take a while. Over 12+ hours of desoldering every chip from the board later, I isolated the problem chips. Of the 10 or so 7400n Chips, 6 or 7 were either showing some continuity between power and ground (anywhere from 50-120 ohms) or shorted to the point it made my meter beep. I set about ordering a load of new 7400 chips as well as enough sockets for all the chips on the board. Even though I've found the short, there's a good chance one or more of these chips won't be working quite right and I want to make it easier to diagnose.
While waiting for the parts I also tested the TV with a DVD player, and sure enough it seems to work fine, as does the sound! I've got all the parts I need to start this tedious rebuild, so hopefully sooner than later I'll have a working (not)Pong machine!
Feel free to ask any questions! ^_^
Hello KLOV:
Just here to show a bit of a project I've been working on. I've worked on a fair few games in the past, but now I'm working on my first TTL game! A 1973 Chicago Coin TV Ping Pong. It's essentially one of many Pong Clones made back in the day. I scored this baby for a whopping $25, untested!
It's missing its coin door and it's plug was chopped off when I got it, but for this price, I couldn't say no! I have some experience with TTL stuff from my engineering classes in college, so I felt like I had a reasonable chance at fixing it. I took it to the shop and turned it on after replacing the power plug. TV came on, but nothing on screen and no sound. I couldn't get the coin counter to kick either. After confirming the power supply was working I found 0v at the board. Eventually I determined the board was shorting between 5v and ground and after removing the a leg off of various resistors and other small components (finding a bad diode in the process) from the board, I realized that it was one of the TTL chips causing the short.
It was this that finally pushed me to buy a proper Hakko desoldering gun. As I realized after removing one chip the old fashioned way, that this was going to take a while. Over 12+ hours of desoldering every chip from the board later, I isolated the problem chips. Of the 10 or so 7400n Chips, 6 or 7 were either showing some continuity between power and ground (anywhere from 50-120 ohms) or shorted to the point it made my meter beep. I set about ordering a load of new 7400 chips as well as enough sockets for all the chips on the board. Even though I've found the short, there's a good chance one or more of these chips won't be working quite right and I want to make it easier to diagnose.
While waiting for the parts I also tested the TV with a DVD player, and sure enough it seems to work fine, as does the sound! I've got all the parts I need to start this tedious rebuild, so hopefully sooner than later I'll have a working (not)Pong machine!
Feel free to ask any questions! ^_^
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