TCS EUN651 equipped loco would not reverse

[Tony_S]

I recently bought a Roco HOe loco that was supposed to come with a decoder but didn't. Until the missing bit arrives I put in a TCS EUN651 placed it on my SPROG track and set it's number to 25. I thought I would then check it and selected a SPROG throttle and it drove forward nicely. I stopped it, selected reverse, but on increasing the throttle it moved forward. As I have an identical loco with an identical decoder I swapped them over, both work perfectly, backwards or forwards. I'm leaving the decoders as they are now and I'm happy that they work but are there any explanations for this behaviour.

 

Tony

[Donw]

Obviously the Gods were having fun with you that day!

Donw

[noiseboy72]

I have noticed this as well with TCS chips if the track is not entirely clean. One of my underground trains has a TCS chip and if it is parked on a dirty bit of track, the direction lights will alternate wildly and the motor will spin in a random direction as it attempts to start. Once running it is fine.

 

I use this as my cue to get the graphite pencil out and give the track a good going over !

[Tony_S]

Ordinarily I would have suspected dirt but the track was clean. Before swapping the decoders I did remove and re-insert the chip. In case it was a pc/JMRI/Sprog problem I had powered everything down and rebooted. I can just put it down to electrons moving in mysterious ways!

I've no idea if there are any capacitors to cause problems as to find out would require now unnecessary dismantling (of a rather small loco) though I was considering it until swapping the decoders worked.

 

Tony