FYI to all .. I ordered a new LRCU1 for my SD-50 direct from Lionel as it was still available for $80, plus shipping and replaced it.. my SD-50 has been reborn and alive and well.. Thanks for all suggestions on how to isolate the problem.. I meant to update this sooner, but it had slipped my mind.
FYI .. On the section of track that is protected by a Powermaster, I also had a relay for a short section of track just before a crossover such that if another engine was at the crossover, the relay would toggle from the mainline voltage of 18-volts for the section the SD50 was on to approx. 6-volts to stop the diesel yet keep the LRCU active so that when the other train cleared the crossover, the SD50 would toggle back to 18-volts and continue on without re-starting the diesel.. but that 6-volt power supply was not protected with a Powermaster .. I have since disconnected my 6-volt power source until I procure another Powermaster which responds extemely quick. The relay worked well many times, but obviously some level of risk .. another Powermaster should resolve
