Paddle-Ball Repair Log

Paddle-Ball arrived in the Repair Station completely dead.  Since the TV in my Fascination Pong Cocktail is also Hitachi I was somewhat familiar with the chassis.  I have still not been able to find a schematic for either TV.  However, as with any old TV, there always seem to be some loose connections and bad solder joints.  Once thse were repaired I tried to power up the TV again.  This time the I was met with full raster but just a white screen.  I connected the PCB but unfortunately had the the exact same white screen.

I shut off the game, disconnected the TV and removed the back. A blown capacitor (220uf 16V) at location C714 was immediately  spotted. This was the identical capacitor that had failed in the TV in my Fascination Pong Cocktail.

Interesting enough the failure was exactly the same where the aluminum can was blown completely off the chassis and the dielectric was everywhere.  I actually found th can in the bottom of the arcade cabinet.  Thankfully  had the foresight to buy two capacitors of this type when I was repairing my other TV so I had one readily at hand.

I replaced the blown capacitor with a brand new 220uf 32V capacitor. I believed the TV was now fixed so I reassembled it and moved on to the PCB and arcade cabinet.  Lucky enough the original wiring schematic was still on the back door!

I was able to confirm the voltage to the TV, coin mechs and lights were correct. The voltage to the PCB was close (10.4VAC instead of 9.5VAC).  All of the chips on this PCB are 74XX chips running on +5VDC but when checking them I found only 0.4VDC was making it to them.  This explains why the PCB did nothing.  I confirmed 9.5VAC was making it past the edge connector but the voltage on both sides of the large blue capacitor was way off.  The only thing in between them were 4 diodes making up a bridge rectifier.  All checked good while on the board but my suspicion was that one or more were bad.  I removed all 4 and found that 2 of them were indeed bad. All 4 diodes were replaced.

The voltages to all the chips on the PCB now tested a very smooth 4.95VDC.  I plugged everything in and was met with the 'attract screen!'  The game was completely  disassmbled and cleaned both inside and out. New locks were installed.  Bring on the pong tournament!