Message #192825

[onetaste]

I have used 1N4148 in the switch matrix in many restorations. The last three system 1's (Genie X 2 and Sinbad) had ALL the switch matrix capacitors changed to 1N4148. They all used Pascal boards. No issues ever reported. The Germanium 1N914 will fail eventually. The 1N4148 are fast switching diodes - perfect replacements.

Did you repin the connectors to the new Pascal board ?

Is the ball roll assy wired correctly ?

Yes, everything repinned at the board. Ball roll assembly ok.

I have spoken to Pascal, there is a diode which I missed, here is what he says:

there are two TILT assys: one under the playfield and one in the cabinet.

each has its own diode.

the diodes for the TILT pendulum & coin door are shown on the transformers schematics page = the page before the one you showed me:


for the coils, 1N4004 are fine (NOT 1N4148, too weak !) for the switch matrix, both diodes must not be used.

it’s a matter of voltage threshold. the original 1N270 germanium diode has a threshold of 0.3V while the 2 diodes you mentionned have a threshold of 0.7V. If you install these switch hits may not register.

any faulty switch matrix diode must be replaced by a schottky diode, like BAT42 BAT43 BAT85. This is true on the original board and my board.

I have finally gotten around to trying to fix this problem. Contrary to the Sinbad circuit diagram, the tilt pendulum wire (pur-wh) does does not go through the diode assembly in the cabinet, it goes straight back to the headbox. There have only ever been 4, not 5, diodes on this assembly since factory. I tried putting a diode in line but this did not make any difference.

My latest thinking is I'll put a capacitor in series with the tilt pendulum. Any tips?

Cheers, Greg