Williams Jokerz - completed
Photo gallery

Thanks to a week off and several late nights, I completed the playfield rebuilding and got the machine operational.  The only power-up glitch was inoperative flippers (I suspect this is why the machine was pulled from its location and sold to me).  Using a simple ohmmeter, I found the problem: burned traces on the back of the interconnect board.  I replaced those with 18 gauge wire and now everything works.

• A footnote about burned circuitry - it burned for a reason.  In this case, the diodes on the flipper coils had broken from impact vibration and it looked like somebody swapped wires to the coils while attempting to fix it.  Desoldering the diodes during the rebuild revealed they were broken right at the diode body.  The rebuilt flippers have no problems now; I highly recommend the updated rebuild kit rather than the original design.

The machine is great fun now.  The ball is silent when rolling on the clearcoated playfield.  The music, lighting, speech and sound effects make it a nice package.  The jet bumpers are very lively (I adjusted the spoon switches to be that way) and that center ramp shot is rewarding.  Here are some neat-o photos of the completed machine.

Click a picture to see an enlargement.

Different low angle	Jet bumper area	Upper playfield

 Finishing touches:

• Pinball Pro speakers and sub-woofer.  Wow.  A must-have modification.
• Latest revision ROMs
• Isolation of U3 from 5V supply on CPU board to eliminate audio hum (per Williams service bulletin, Original JPG, MS Word DOC, or PDF)
• Batteries replaced with ferromagnetic RAM non-volatile memory chip obtained from Pinball Lizard.  Settings are retained with absolutely NO batteries needed!
• New display glass (the 16-character alphanumeric plasma displays)
• General illumination connector fix (underengineered in System 11 games like this one)
• New playfield glass
   

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