Zimo chip keeps resetting itself

[OllyW]

Hi. 
 

Wonder if anyone could help me.
 

I have a zimo mx648 sound decoder which keeps resetting itself to default after a while on the track. 
I’m addressing it to / want it to be loco 27. It’s got an A4 sound file on it. The reset doesn’t scramble the sound file however the address keeps resetting to 3. I can’t work out what is causing this.

My programming track is a completely separate entity from the layout and I’m using a digitax system. No other locos have this issue including others with the same decoder.  

 

I can’t see any wiring faults on the loco. 
 

Any help that can be given would be appreciated. 
 

Thanks in advance. 

[Torper]

If you've only had the decoder for a fairly short time, I suggest that you tell your supplier about the problem.  It may be that your decoder is faulty and if so your supplier should replace it.  Meanwhile, if you happen to have another decoder handy, it might be worthwhile fitting it to the loco as a temporary measure and seeing if you can change the address using that.

 

DT