Tam Valley Depot Quad Pic - powering three points

[Tickplan]

I have a rather complicated - but flexible - system for powering my points. The points are in the main operated by Cobalt (stall) motors. These in turn are connected (via a Tam Valley Stall Motor "daughter board") to a Tam Valley Depot Quad Pic Auto Servo Driver. This is connected to the DCC power bus. Power to the Cobalts is from a separate 12 volt DC supply. What this enables me to do is to operate the points either by issuing an accessory command on my NCE Powercab controller or, more commonly, by throwing a lever in a lever frame which in turn operates a microswitch which is connected to the toggle inputs (Signal System Inputs) on the Quad Pic. The two methods of control are I am told "opto-isolated" (whatever that means!) but I have had no problems using this (together or separately) over a number of years. A number of "paired points" - crossovers and the like- are operated together and function as if they were one point. I also have one set of three points also operating as one (with two Cobalts and one point operated by a servo).

This has all worked well for some time but recently I have had problems with the one output  which serves the three points. Operating the lever frame - and therefore the microswitch - for most of the time now does nothing even though the other levers/switches are working/operating the other points. I have checked the microswitch and it is OK. Interestingly, I can change these three points by issuing an accessory command and in this set up they work as normal/as they should. Occasionally, the system does come to life and operating the lever does work the points but they are very slow to respond to the signal and when they do move they are sluggish. It is possible that they are only operating in one direction - I need to be more observant!

I know nothing about electronics and only a little about electrics but it seems as if the points are not getting enough power, or signal to make a change. I don't understand the power thing since the Cobalts are fed from their own power supply and in any event they work when actuated by an accessory command. I seem to remember (it is a while since I put my head under the baseboards!) installing a Tam Valley Accessory DCC Booster to help with this sort of thing. The servo is from memory using the DCC bus power rather than have its own 5v supply. Could this be draining power away at the same time the Quad Pic is asked to change points for the two Cobalts? That said why did it work before?  I have bought another Quad Pic but installing it will involve some under-baseboard contortion or removing the boards altogether - not a simple job. I also did not want to install it and find I had the same problem and without knowing what the problem and its possible solution would be.

Sorry this is a bit long. I hope there is somebody out there who understands and can help. Thanks in anticipation.

 

Bryan

[RobinofLoxley]

Since the Cobalts work properly when the accessory command is employed, this would seem to eliminate anything to do with power supply.

 

What you say suggests something is wrong with the lever frame itself. Its hard to know what that might be without a description, but I would be thinking about cleaning it.