If anyone has come accross the problem of some MTH Protosound 1.0 locomotives not working with their own Z 500-Z 1000 transformers and if you collect MTH trains you probably have. If you give MTH a call they will tell you that you need to replace the top board and sound chip. That is bogus as you only need to replace the sound chip. I have done this on three Premeire locos and it has worked every time. MTH still has plenty of chips for 37.50 so if you have this problem give this a try. I did order PS 1 chips for RK locos instead just in case.