Thomas Troubadur Organ turns on and lights up but no sound when keys are pressed

SOURCE: looking for a schematic of the Casio ctk-700 to

The keyboard is LIKELY scanned as a matrix.

You have two problems:

The contacts in the Thomas will have to be totally disconnected rendering use of any of the Thomas organ unlikely.

The second problem is that the keyboard LIKELY has velocity sensing. This means TWO contacts must be used PER note. One contact "makes" first and "breaks" last. This is used for velocity sensing on synths. The Thomas foot pedals likely only have a single contact per pedal, and even if they had two, it is unlikely they sequentially close..

The matrix scanning is accomplished by sensing the connection of two crossing points on a matrix of circuit lines. USUALLY each of 12 wires tie to all of one note across the board. Then two other lines for each octave "strobe" the first make contact and then the second of those strobes the second make contact. There are two of these strobe lines for EACH octave on the board.

Remember that these lines scan at digital logic speeds so wire length and NOISE/STAIC DISCHGARGE PROTECTION is a must.

SOURCE: Thomas jester 132 organ troubleshooting E-flat

Here is where you can get the service manual:http://celedoniaorgan.netfirms.com/cosco/nfoscomm/catalog/product_info.php?products_id=1021&osCsid=3eaaa99d6bfceeaaf9b844687ba58d55 Since the problem is with the foot pedal note and the keyboard note I would suspect that there is a problem with the tone generation circuit for that note. You might try cleaning the key contacts on both for that note first to see if that works. The volume pedal probably just needs the volume pot cleaned with contact cleaner spray. I hope this helps. Let me know if it does.