Runaway locomotives

[C37]

I have tried reprogramming the decoder cvs for by using a running road to programme.
The wheels simply went a million rpm and then eventually cut out altogether.
I now have 2 inoperable powers cars for both DCC and DC with the blanking plates. I fear motor burnout?
Nightmare.
Any ideas welcome.

[RAF96]

I don’t have a Powercab but no doubt it tells you in the manual.

[Brian]

While I have a PowerCab I haven't set it to Programme mode adding a loco as its not normally necessary.
I would place the set or just one power car at a time on the main and switch On at the mains socket, then immediately hit the Emergency Stop red button. Assuming the unit stops then with speed set to zero slowly increase the speed to see if that has worked.
If it doesn't work come back and we will try other alternatives.

[Phil s]

This may not help but have you tried a different decoder? I had a similar problem a while back, one of my Bachmann class 37s (had a factory fit decoder). Worked perfectly for years then one day when I switched power on it set off at full speed and would not respond to any command from the controller. I swapped the decoder with a spare I had and it has worked fine ever since.

[C37]

Hi Phil, I am going to order a couple of 21 pin decoders to test this possibility. Come to think of it, I have had q loco that has misbehaved randomly until decoder replacement.
After that, not sure what I'll do as I don't want to throw good money after bad!

[C37]

Brian, I did try hitting emergency stop, it had no impact unfortunately

[IanS]

I assume (but could be wrong) that you've taken the decoder out, checked for bent pins and reinserted it without success. I recently had a loco that decided not to run at all - this was the solution.

[Brian]

Brian, I did try hitting emergency stop, it had no impact unfortunately

In that case its highly likely the decoders are defective.
But I would always check them if possible by either fitting them into another known working loco or by using a decoder tester.
21 pin MTC decoders new are from £18 up so perhaps testing them before purchasing new replacements might be a better option - Assuming you have another loco or tester that accepts 21 pin MTC decoders?

[C37]

Unfortunately don't have any other locos with the 'female" mtc type. I've bought a couple to try, fingers crossed they will do the trick

[Walkingthedog]

And of course make sure the track and wheels are meticulously clean.