The first one was the unit was becoming hot near the sensitivity pot, a more noticeable problem was the car not slowing effectively and sensitivity diminished, and finally, the model track speed can be controlled by twisting the sensitivity pot, without any trigger application! There have been several rumours as to what the fix might be, from replacing the power transistor to replacement of either or both pots. A bit daunted by this I dashed off an email to Professor motor to get their input.
I received a very prompt and courteous reply which was helpful. They have suggested that there is no one problem that it might be but highlighted the fact that there were two very important guides to follow with this model number. The first is not to use this model (PM 2110) with tuned or high powered / current motors. It is rated for 12 to 15 volts. Guilty! and the second is that the controller has to be serviced regularly, i.e. remove the covers and clean all the accumulated dust and rubbish from the circuit board and semi conductors (guilty again). This dust can bridge the circuitry. It is also essential that nothing except the recommended lubricant must be used on any part of the controller, especially the wiper arm and contact surfaces.
My controller returned to normal after cooling down but some more laps showed the transistor was heating up again. So when I returned home I removed the casings and sure enough, there was dirt on the circuitry and even some fine spider's webbing!! I have cleaned and lubed the controller and will be trying it again soon. Hopefully the cure is complete, but time will tell. I may even review how the controller is transported from meeting to meeting! Check out the following links :
Professor Motor spares
PM 2110 service instructions
PM do offer a repair service, you will need to contact them at :
Professor Motor Team Support
32104 Plymouth Rd.
Livonia, Michigan 48150
Office # 734.462.4226| Fax # 734.462.4211
Lightning Speedway | Retail # 734.462.1700
http://www.professormotor.com | http://www.lightningspeedway.com