z21 ruined 3 older NCE decoders

[posneg6]

Hi all, At the risk of being a pain I have posted this before but I can not get an answer and it's driving me nuts! It seems that if you place a loco on the z21 live track it does something strange to older NCE decoders. I have about 12 such locos all are running well but then I added a loco onto the live track and it went beserk same with two other loco's they will not work on z21 even though I have tried reseting the z21 deleting all locos from Multimaus library and resetting the locos Cv#1 and NCE CV#30 back to 2 which should reset the NCE. Done all that and the locos still will not respond to the app or Multimaus. the only thing they do is go full speed when I press the stop button then when I press again to start, the locos shoot off at full speed for two seconds. yet they all work fine on the older Rocco DCC set up!

Anyone have any suggestions or should I, A, throw away three previously good decoders or B, flip the z21 to ebay?

Any help greatly appreciated.

yours sincerely frustrated of Sydney.

PS I'm not certain if the decoders are N12SR or N14SR or even D13SRJ .

[PaulRhB]

What voltage have you got your Z21 set to?, some of the old decoders are sensitive to it being set at default 18v. They seem fine if you reduce it to 16v. Had a similar problem with a broadway trackmobile which is factory fitted with a newer micro nce decoder which seems to overheat after a couple of hours. Take it off for a while and it is ok.

[Edwin_m]

No personal experience but chat on forums a few years ago did suggest that Americal decoders were more sensitive to higher track voltage as many European command stations produce by default.  If you reduce the voltage, remember to "coin test" the further parts of the layout, as less voltage means less current and if there is a high-resistance section it could push the current below the limit that works the overload protection. 

[posneg6]

Hi All, I finaly sorted out the problem! I got onto Rocco through the rocco site that is active as the Z21 site is having Captcha problems.

They instructed me to turn off the railcom toggle on the app, I did so and BINGO! all is well in my little train world once again. Even the Hornby RLM works 50% of the time. I easily managed to programme firebox flicker onto F1! Thanks to all who tried to help me on this one.