Hi Les,
Been out all day so just checked this thread. Let me try to answer some of your points (as best as I can anyway!) First the history, the next door neighbour gave me this last week as he is moving. It is almost new, just out of guarantee..typical!! it did work, but when brush stopped working, he changed the belt obviously nor realising that there were two motors! hmmm! Now the pcb receives it's power via a micro switch (bottom of pic ...301 to left of tube) this switch is cam operated by the handle being up or down (I forget which way the on/off is set) It is mains powered, the brush motor is 230V dc. In pic ...301 the motor is on the lhs of the pic connected by blue/ red wires. The white sheath brings + and - from mains input and "carpet " switch to the pcb via the "cam micro switch" the other red/blue goes to the reed switch. no hidden connectors, pcb fuse ok To run motor (bypass) connected the two wires from the white sheath (blue wire is to a spade terminal on board) to a light bulb. Also tested motor with car battery ran ok but slow , didn't want to put ac through it. Hope this helps. Where is the board available from ? £26 seems very reasonable.
Regards, Steve.