fredag 20 april 2012

Some earlier projects

I went through my hard disc and found some pictures of older repair projects.

Bally Corvette
This was a tricky case. Sometimes the LT-5 engine in the top left corner didn’t move as it should. Instead of the smooth movement from side to side and engine like vibrations it just flip flopped from side to side. To find the cause of the problem I had to disassemble the motor unit, which included removing ramps and a lot of playfield parts. The cause of the fault was a bad soldering at the magnetic sensor that feedback the engine movement to the servo circuitry. By the look of the soldering, lack of tin, I suspect that this has been a problem in this machine since it was new.  


While having the playfield disassembled I gave it a good cleaning and polish, it really needed it. The ramp protector for the left side of the LT-5 ramp was missing, so I made a new one and also changed all rubbers. The owner of the game called me after a few days after it had been delivered back complaining that the multiball lock didn’t work as it should. I made a home visit to check the multiball difficulty setting, which was set as liberal, but even though the game acted as the setting was at the hardest level. I changed the setting from liberal to the next level and back to liberal and rebooted the game, and now it worked as it should.

Bally Playboy
This was a fun case and I really enjoyed working with it. The game was in really bad shape, and if it had been some other less valuable model than a Playboy it might had been a case for the scrap bin. There were a lot of faults in the electronics and a few MacGyver solutions, when one fault was repaired another one popped up. Finally I got the electronics working and turned to the playfield and cabinet. The playfield was badly worn, but it had all its original game specific parts. That’s a good thing if someone in the future would like to swap the playfield to a reproduced one. I disassembled the playfield and cleaned and waxed it. I also went through the mechanics at the underside to make sure it worked as it should. The cabinet was cracked in the front corners and someone had tried to repair it with screws and nails. I think I removed about 30 of them to be able to open the corners and glue them together again. Also one of the legbolt bracket was more or less loose in at the inside due to some missing wood.



 
 


Gameplan Sharpshooter
This was a quite straight forward case. The CPU didn't boot due to acid damage from the battery and faulty ROM chips. I cleaned the board, repaired the acid damages and rebuilt it to run from EPROMS. Then the usual disassembly of the playfield, cleaning polishing assembling and new rubbers.
When repairing this game it was the first time I tried out my home built tumbler to polish the metal parts. Maybe not as nice looking a factory built one, but it does work.