trouble shooting speed controller issue for a large format train (thomas and fri

[plawson]

Hi all

Grandpa (my dad) bought my son his first model train this year and we set it up for Christmas.  after a few times around the tree it stopped working.  I checked all the connections and everything was snug.  I noticed the red light on the speed control was not turning on.  I took out my multimeter to try and find the issue.  I read 20V on the power supply.  I tested on the cable termination and on the board of the speed control with the same results (i.e. power is making it to the input on the speed control).  I then checked the continuity on the led light to see if the light was broken and it lit up so that's good.  I also checked the continuity from the track connector (the 3.5 mm  connector) all the way to the track clip and even to the track itself once attached.  This was good.

I've determined that something internal to the speed control has stopped working.  Rather then paying $80 for a replacement to see if that works, i was wondering if there was a circuit diagram available that I could uses to trouble shoot.  I would have assumed the LED light was directly connected to the power in but it seems to not be the case as I tested good power to the board on the input jack but not to the LED.

Any thoughts or preferably design documents would be helpful. 

Thanks,
Peter

[Loco Bill Canelos]

Hi,

Sorry to hear about your problem.  You may want to call the service department to see if the controller is covered by warranty, since it appears you just bought the set.  There is nothing repairable in the controller.

I was wondering if the speed controller worked then stopped, then worked again for a while and stopped again, or did it just suddenly quit and never work again.

These speed controllers have an internal thermal circuit breaker that heats up when a short occurs and breaks the circuit.  After a cool down period and assuming the short is removed the controller will work again normally unless the short is not removed or discovered.  Tinsel for example can cause a short. If a short is not removed,  the thermal breaker will trip again and again.   After a time and many trips, a thermal breaker will fail completely and the speed controller will not work at all.   If this is what happened to your controller it is not really repairable.

If the service department can not help or if you had the set for too long, your best bet is to go on ebay since they seem to go for around $40 or much less.  they are often bundled with track which you could use for expansion.

Here is a buy it now controller only for $20:

http://www.ebay.com/itm/Bachmann-Train-Analog-Power-Pack-and-Speed-Controller-1-AMP-/361263204088?hash=item541cf706f8:g:bBoAAOSwv0tVIthm

Good luck getting your set running again!

Loco Bill