I had two Williams Flash machines that I recently shopped out and got back to working 100%. I cleaned, re-rubbered, and waxed both machines. Both games had similar problems with different fixes.
Problem # 1
One machine did not have any background music. Flash was the first machine to have continuous background music. Machines prior to this would only sound if a certain feature was hit. This is a great feature on this game, and deserves to be working. The operator has a choice of turning this on or off in the adjustments.
Green ROM background sound = 31
Yellow ROM background sound = 33
00 = Off
01 = ON
This game had Green ROM, set to 01 on adjustment 31, and still no sound.
Q13 on the driver board generates the background sound. Following this signal back lead to a bad chip (PIA IV). Once I replaced this chip, the sound was back to working!
On the same machine, the credit knocker was burnt to a crisp. This is generated by Q15, and it was bad. I replaced the TIP122 with a TIP102, and the credit knocker was back to knocking.
The other machine had one coil that would lock on. The left slingshot would lock on as soon as a game was started. This is in the special solenoid section and ended up being a bad chip (U9-7402). I had good signals going into the chip but the output was floating. I tested this chip in my tester, and it flagged gate 3. Gate 3 is the one that controls the slingshot. Replaced the 7402 and slingshot was back to kicking.
Both machines needed the drop targets cleaned and adjusted. This is a common problem with this machines. When the drop targets fall, they contact a board that’s attached to them. The boards and contacts get dirty and will create intermittent issues. I cleaned up the drop targets and the boards. It’s a little bit of trial and error to get the right adjustments, but the drop targets were falling and now resetting once they were all completed.
Both machines needed work with the pop bumpers. Both machines had skirts that were broken. I replaced the broken skirts and adjusted any other problems with the pop bumpers.
I have had my Flash for quite some time and really enjoy the game. Quite a few things to shoot for in the game such as drop targets, spinners, loops along with 3 flippers. I was happy to get another one in my shop and new owner will be happy with it!