Henry, I'm not sold on the board being bad. How slow is the locomotive moving when going through this bad spot? If both rollers are moving through a dead spot slowly, you can expect the engine to shutdown. If you turn the engine around on the track and run it the other direction or just run it backwards through the same spot, does it shutdown?
I have another SD60 engine PS2 5 V that I tested as well. Both engines were tested at 50 smph and in both directions one has no problems the other stops abruptly and sound stop as well. The layout has been down for 2 years now and I did not have any problems with the engine in question until yesterday. I have 2 areas where there is 2 spots that this happened. I still think its the something in the PS2 board. My layout is a large one about 50'x10' with 4 levels, 51 switches, 38 engines all DCS