Church Organ Repair – Livinston Choral 30

It’s not very often that a job comes in that takes you back a few years, but occasionally one turns up that takes you back in time, reminding you how electronics used to be.

Livinston Choral 30 church Organ

Livinston Choral 30 Church Organ

It was a 35 year old electronic church organ, made by a company called Livinston, that brought back memories for me. It was their Choral 30 model and had a memorial plaque in the centre of the front cover detailing the benefactor of the organ to the church at that time. They always make an attractive piece of furniture with their wooden casing.

The owner of the organ informed me they had only had it for 2 months, and had noticed several things wrong with it. Because of this I decided to workshop the organ, so that it could receive the care and attention it deserved.

Initial problem – no sound from the organ… at all!

The original fault description was that there was no sound coming from the organ at all. Easy fix I thought, that will be a problem with the power supply. So I went armed with all the most probable components for a faulty power supply, only to find that when I arrived and inspected the power supply, all was good.

The fault was traced to a bad connection with the headphone switch… which then highlighted the next problem. There was a loud “motorboating” sound coming from all the speakers. Very much like a large heart-beating type of sound.

Inside view of Livinston church organ

Church Organ – Electronics Board and Power Amps

Main electronics board and power amps

As you can probably see from the picture there are three separate power amps (centre of the picture, bolted to the back panel in an upright position). Fortunately each one had its’ own fuse, so it was quick to determine which amp was the culprit on this occasion.

With that problem out of the way, I thought it would be time for a celebratory cup of coffee. With the power switched back on again, a quick run up and down the keyboard revealed several keys not working. It was then that I remembered, that if it wasn’t for bad luck, I would not have any luck at all, and so the coffee would have to wait. It quickly became obvious that it was the same three keys across all the octaves (“A”, “B”, & “C”), that were not working. On this model there is a central oscillator IC (Yes they did have Integrated Circuits 35 years ago!), with a divider for the 12 frequencies for each note, which are then continually divided down by 2 for each octave. The scope helped to show which of the divider chips had gone faulty.

Tracking down a 35-year old integrated circuit board

Obtaining an IC that was made 35 years ago, but is no longer in production can prove to be a bit of a problem. This is where the experience of an engineer is what the customer is paying for. The parts were ordered, and when they arrived were duly fitted, and I could now play three blind mice in any key I chose. Ok so I am engineer not an organist. I chose the key of C.

Now was the time to check all the different stops. The 16’ stop on the lower manual was not working. That was traced to a resistor going open circuit on the main board. A lot of resistors of this period were carbon film resistors, and this can be quite a common problem. With all the stops now checked and working I had to make sure that each key worked with every stop.

Key spring contacts

Key spring contacts inside a Livinston church organ

Key Spring Contacts

As can be seen from this picture the contact system is quite rudimentary. There are 5 horizontal bus bars, and each key pulls on a bar (the pink vertical plastic rods), which then bends a spring to make the contact for that note against the bar. The main problem that you have with this is corrosion and dirt, which can make for bad connections between spring and bus bar. It is a fairly time consuming process to find out which contacts need cleaning, and then very carefully cleaning them with the correct cleaning agent, without breaking any of the springs.

Bass pedals on a 35-year old church organ

Church Organ Bass Pedals

Fixing the Church Organ Bass Pedals

The last part of the job was to check the bass pedals. The multi-pin plug was connected and much to my surprise they all worked without any problems. Maybe the sun does shine on the righteous after all.

Now for the final test. I am fortunate in that I know a church organist, who I invited along to come and play the organ. He gave it the thumbs up, so we finally had a working 35 year old church organ and a job well done. Now where is that coffee jar….