Wurlitzer d72 Upper Tibeas, Pistons, Strings and Celeste out of wack.

[Eddy67716]

Tomorrow I am getting a Wurlitzer D72 from my church. but it has a few problems.

The Upper Celeste when off stops the non tibea sounds from playing in certain octaves.
The 16 and 2 tibias are stuck on in the first half octave of the upper manual and after the first C# to C octave they are stuck on too. In the first C# to C octave the one foot tibea is stuck on.
The pistons can only save on combination on all the pistons.
The 8 tibea doesn't work at all (But I thinks that is because the spring switch is crooked.
The string ensembles are hard to toggle on and off. They have to be pressed several times.

I think the problem is a circuit board below the upper manual because I followed the wires from the pistons to that circuit board.

Any ideas on what could be causing all this and solutions?

[Eddy67716]

I think that the last person to restore the organ did a weird job. Some resistors are soldered in serial and some in parallel. The 8 tibea's spring is conducting current. I used an LED with a 330ohm resistor to test it.

[you795a]

If you are in the US, you can try contacting Morelock Music in Rienzi MS. or W.D. Greenhill in England.

[Eddy67716]

If you are in the US, you can try contacting Morelock Music in Rienzi MS. or W.D. Greenhill in England.

I'm in Australia.

[Eddy67716]

Oh I've found out more on the first C# to C octave in the upper manual. All the tibias that work fine also work well in that octave. I think only the celeste pitch plays because it doesn't beat. The vari voice also is cut off but a faint octave sound plays.

[Eddy67716]

Would anyone know where to find a service manual to a Wurlitzer D72 Organ?

[you795a]

It might be expensive for the shipping since you are located in Australia, but Morelock Music in Rienzi MS in the USA would have them. You could always email them.

[tucsondave]

If it was in a church the first thing I would check for is signs of rodent damage.
This is a multiplexed LSI organ and the service manual covers the 170, 72, and the 172. The manual is 144 pages most of which are 3 page fold-outs. There is no troubleshooting information and no overall theory of operation explained. If the issue is in the multiplexing circuitry you will most likely need an oscilloscope.

td

[Eddy67716]

There is some mouse poo in the frame but nothing but dust on the circuits. I haven't found any broken wires yet.