Tennis Tourney PCB Repair

Hello,

I just finished repairing a PCB from this game, and I learned a few things
while I did.

First off, I only have the PCB and no cab. I thought it was a "Paddle
Battle" since that's what it says on the board - Apparently they didn't
bother to label it as Tennis Tourney.

Originally it was DOA, with a masking tape labelled "Zilch - no sync, no
audio".
Visually there was some heat damage near one chip, the last 7400 before the
audio output. It probably latched up at some point.

The power supply was fine. I replaced a 9316 in the vertical counter chain
and the raster fired up - scores, but no ball, no audio, sometimes no
paddles (coin up would reset the scores, but the paddles wouldn't always
show up)

I replaced the 7400 and the audio started working.

I found that the PNP/NPN latch used in the coin circuit wouldn't stay
latched. Furthermore, I realized this circuit is absolutely unused in the
Allied Leisure versions of Pong, unlike the Atari version. So, I just
grounded the output - and the paddles work fine every time.

I replaced another 9316 in the vertical ball position counter, and now it
works 100%.

-Frank

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Received on Mon Aug 16 12:38:51 2004