Troubleshooting

I noticed the following problems :

- The solo and principal group sound less loud then the tibia's
- Percussion switch and slider do not seem to have any effect
- The vibrato slider does not seem to have any effect
- The light of the on/off switch does not work
- The light in the volume pedal does not work

At first I suspected all these problems had a different cause. But studying the schematics learned me all these problems had something in common.

They are fed by the -20V supply off the power supply. Doing some measurements on the power supply I found out the -20V supply was completely dead.



Then I found a fried resistor (picture red arrow). Seems I have shorted the -20V circuit while working on the organ. I remembered the first day I was working on the organ the power light was still working, at some point it stopped working. I thought it was just the bulb that had gone dead.
Exchanging the resistor with a new one fixed the problem.

Cleaning upper manual key contacts

During my experience cleaning the contacts of the lower manual, I learned cleaning the contacts has to be done very thorough, to have a good result.

Therefore I decided to remove all of the plastic spring guides, so I could reach the bus bars and the springs very well for cleaning. In the first picture you can see the key contact print with the plastic spring guides removed.

For cleaning I scratched the bus bars and the springs with a small flat screw driver. It takes a lot of hours scratching every spring a few times and the bus bars on every spot where the springs are supposed to make contact.

Now the hardest part; getting the plastic spring guides back in. It is very time consuming to say the least if you have to do it without an aid. I gave it some thought and put threads in the springs to make them longer. Then it is easier to guide the springs into the holes. After you have put the plastic spring guides in, you take the threads back out.

Here you can see how is necessary to make the springs longer, to guide them in the holes.