Crumar Multiman

[Alan3666]

Hi everyone

I've just bought an old (1975) Crumar Multiman. It was sold as parts only. The vendor said the kettle plug socket was broken but you could still plug a cable in and the red led came on when powered up but there was no sound.
First thing I did was replace the broken socket and check the fuses/voltages. The keyboard hinges up to give good access to the power supply. I found schematics online. Fuses all ok. Checking voltages I found 22V was sitting around two volts. An educated guess pointed to the 22 volt zener diode on the power board. I cut out the zener and sure enough it was shorting in both directions. After soldering in a replacement zener I now have all the voltages and it is generating sound. The faders are all very scratchy. I sprayed switch cleaner into the faders which has improved things but still not great.
It looks to me that the faders should be removable, plugged into the sockets on the board but it looks like someone has soldered all of them in. Can anyone verify this?
If you fiddle about with the faders you can get all voices sounding fine, as well as bass.
So as it stands I have everything working except the first three Brass envelope faders, Attack, Decay and Emphasis no response, Contour working fine.
I've also found that some keys don't sound with some voices. So a key that works on brass might not sound on piano for example.
Each key has a small module which can be unplugged and swapped around. I was going to move the silent keys out to the outer parts of the keyboard but that was before I found the silent keys work with other voices.
Does anyone have any advice on faultfinding these keys.
Its not such a big deal if I cant resolve, the sound that it does produce is very rich and with all voices switched on you hardly notice if there are some voices missing.
Any help or advice greatly appreciated.
Alan