Wurlitzer Lyric M 1964 credit unit question

Greetings once again!

I recently bought a Lyric, and am very happy with it.

I wish to have EVERYTHING working correctly if possible, and the only parts which were a problem were associated with the coin/slug rejector/credit unit. The 'box plays well, with a "free play" switch added, to advance the 20 pfg sloenoid...

I have replaced the munzprufer, and now have all three contacts which the coin hits, advancing the credit wheel correctly. Each selection "decrements" the credit wheel by one play- perfect!

The last remaining problem has, so far, defeated me.Within the credit unit, there appears to be a pair of contacts which are CLOSED in all positions where there remains some credit, and they OPEN when the credit is zero.

This MUST be connected in some way to the 24V lamp on the display which confirms that credits remain. THis lamp does not work, even with a new bulb, and does NOT have 24V across it even when credit is added.

In the schematic there is a large capacitor shown with a resistor- but I do not understand its function. I can measure a voltage on either side of the capacitor relative to ground.

Can anyone help me with some more diagnostic info, or suppy info about the role of the capacitor, and if they tend to break. Should I try to buy a complete credit unit and replace it?

Please let me know your ideas- in German is also fine as I can get a colleague to translate if necessary!!!

As Ever, many thanks

Morgan in Luxembourg

Hallo morganrue

Wich Capacitor do you mean?
The 50uf Capacitor works with the selector relay and works not direktly with the credit Lamp.
Do you have an Service Manual?
Normaly you must mease 24 Volt azt the bulb when to Credidswitch is closed.
Is the Resistor before the bulb right? ( 120 Ohm 1/2 Watt)?
The function of the Lamp is very simple:
Is is connectet in serie from minus from the rectifier - 4A Fuse - 120Ohm Resistor - Bulb - credit switch - ground (+).

Best regards

Smitti

Hello Morgan

One terminal of the credit lamp is connected to the supply voltage via a resistor. The other terminal is connected to ground with the contact, if credit is available. Therefore, on one lamp terminal (whether credit is available or not) have to be measured about -24 volts to ground. If not, the resistor is probably faulty.

The large capacitor is part of the selection system. One terminal is also connected with the supply voltage via a resistor. The other terminal is also connected to ground with the same contact as the lamp. The capacitor is charged thereby via the resistor. When selecting, the charge of the capacitor is used to operate the selection coil. By this circuit, it is ensured that only a short pulse comes to the selection coil.

If the capacitor has to be replaced, you have to know that the positive connection of the supply voltage is grounded. On most available capacitors the negative terminal is connected to the housing. It must be ensured the correct polarity and the capacitor must be mounted isolated. The housing of the capacitor must not touch the chassis.

Best regards - charly49