This machine was pulled out of barn in grim condition. Stuck buttons and a non-working
MPU3. The frames were badly rusted and the coin mechanisms were all corroded and
The MPU3 was repaired (covered in the repair section) and the buttons were stripped
apart and put in the dishwasher. The frames were rubbed down and painted blue. The
diode on the start button was destroyed so that was replaced.
The mask was damaged and had to be repaired. The coin mechs were still on old money
and we’re freed up using WD40, I put the manifold and pipes in the dishwasher and
cleaned the inside of the machine. With the MPU3 and the bulbs replaced it was time
SRU type steel holders were used with no diode. All MPU3 and MPU4 multiplexed lamps
must have a blocking diode fitted. If not, current feeds back through the matrix
causing lamps to light when they should not. I ‘borrowed’ some from Beat the clock
which are spade –connected and are of the same type. After hours of trial and error,
I replaced all the holders and eventually got the polarity correct so that all the
lamps correctly light.
Finally, got round to the reel deck, changed the sensors and after a bit of messing
about, I got rid of the reel alarm.