In the hand controller I repaired there were 2x 9Volt batteries, which if the motor controller fails should return the chair to the upright position. In the hand controller I repaired, the batteries had been wired in parallel, which was wrong, because when I rewired these in series giving 18volts it worked. I then checked the rest of the wiring and found a short which had blown the quick blow fuse in the motor controller (under the chair)To gain access, slide the base off and remove the screw.The system itself appears to work on 21Volts from the transformer.
JAMES MCNAMARA
October 2008