I am not sure if I am in the right place for this but I have a problem I would like some help with. I have an MRC TECH 11 3000 controllerwith cab control. Sometime ago the heatsink on one of the tansistors came loose and the transistor burnt out.The tans is marked from I can make out D1230. I am having a job finding a replacement or its equivelent.Can any one help me in this respect?