Good evening. My T1 is heading to Florida as I type. After I called BLI and listed the symptoms, along with the fact the engine ran briefly before toasting the second decoder, probably means there is either a pinched/shorted wire somewhere, or one of the printed circuit boards has developed a short. I remember the latter became a problem when everyone had to go to lead-free solder. The solder would over time grow and bridge the tiny gaps between joints, causing shorts. I'll see what turns out to be the problem in 2 months, which is their current backlog.
In other train problem news, my new RTR SD45 has a bad motor. I scrounged up a really old decoder, assembled the SD45, sans lights (just the motor connected), programmed the decoder, and ran it for a while. At first, it ran okay, drawing nearly an amp. After a few minutes' run time, it began to slow down, the decoder began to heat up, and the amps climbed. I shut it down just before the motor began drawing 2 amps. The decoder was hotter than a firecracker, but the motor, strangely, was cool. A mechanical bind would have caused the motor to also be very hot. So, it looks like a simple case of a defective motor. I still have the other defective motor, which did almost exactly the same thing in another locomotive a couple of years ago.