Futaba Display fixed!

Tonight I replaced the zener diode on the power supply for Solar Ride.

It is a pain to work on the power supply board - the main power transistor is soldered on through the chassis, so you have to desolder it before you can remove the board from its carrier.  All things considered, though, it went fairly smoothly.

A new RottenDog power supply would set us back $100 or more.  This fix cost $12 - and I got lots of spares, if it happens again.

But it works!  The displays no longer share numbers.  Now, I have to sort out the high scores - but for that I will probably just get a 3xAA battery holder and get some cheap NiCAD or NiMH batteries to stay in here forever.

Up to Potential

We've had a Gottlieb Solar Ride pinball for a while now, and it has had consistent problems with the displays.  They have ghost numbers - the score on the first player display will appear on the other displays as the numbers increase.

Yesterday I traced it down to a failed zener diode / resistor causing the +8V reference voltage to go away.  From the Futaba web site:

"If the filament potential is lower than the anode and grid cut off voltage, thermionic electrons can reach the anode and cause illumination of the phosphor. The filament bias voltage should be increased to prevent this problem." 

Naturally.