Sad couple of weeks for my trains

Just as a Hail Mary type fix, first try changing your track power source and wiring to the track (or better yet, use a dedicated test track) to ensure the absolute lowest resistance path.

Then reset your "blinking" engines as follows:

i. With power on track, press the “R” with the octagon around it. The engine should respond with a short whistle.
ii. Turn off power to track
iii. Turn off the command base power…to stop TMCC/Legacy radio frequency from reaching the track
iv. Wait about 30 seconds.
v. Restore command base power
vi. Restore track power.
vii. Turn speed wheel to move forward

Nothing to lose by trying this before you perform surgery!

Thanks for the info. I will give it a try. Good news is i got the lionmaster big boy smoking again