Syntech/Chroma Cult Service Note
Attention Chroma Owners With Serial Numbers 0011 Through 0439
If the last four digits of the serial number on your Chroma are between 0011 and 0439, you should be aware of a potential problem with the interface circuitry in the Chroma. I have included a copy of the Rhodes service bulletin regarding this [FCN3-007]. Several owners of the Chroma to MIDI converter have reported problems that ranged from intermittent operation to the box not working at all! In each case the problem has been traced to a wrong capacitor value on the Chroma I/O board.
If you have a problem when you first plug in your converter box where the box won't work or seems to hang up once in a while, don't panic. You can either replace the capacitor inside the Chroma with the correct value as outlined in the service bulletin or simply cut the capacitor out of the circuit. I prefer the latter. Eliminating it altogether will have no adverse effects on the performance of your instrument and will improve the performance of the computer interface.
The diagram in the service bulletin of where the capacitor is located isn't all that clear. When you open up the Chroma, the front panel flips up, exposing the I/O board and the computer board. The I/O board is the big board in the center. In the lower left area of the I/O board you'll find the tapper. It's a metal bracket supporting a solenoid. Immediately to the left of this you'll find an IC (chip) labeled Z48 (the lettering is upside down). To the right of Z48 are three small components, a capacitor, a resistor, and another capacitor. The capacitor to cut is the far right one, next to the tapper.