I was running my MTH/Railking Rudolph The Rednosed Reindeer engine and tender recently (yeah, I know the holidays are over, but I LOVE this engine and tender and decided to give it a post-holiday run).
It started to exhibit some odd behavior. Every once in a while, the engine would suddenly lurch forward with a FAST BURST of speed, then quickly slow to the original pace (with the sound of squealing brakes as it decelerated back down to the initial speed). It just happens randomly while traversing the track. In addition, I noticed that the engine headlamp would be on for a while (it's a red blinking light), then go off for a bit, the go on / off.... etc. It seems very erratic.
Could this be a sign of a dying Protosound battery? 
All of the audio sound effects play normal -- clear as a bell. Even the sequence of Protosound audio clips play fine (when triggered). The entire routine works perfectly, including the automatic start-up of the engine when the set of audio clips are completed.
I am running the engine on Lionel Fastrack using a 100W MTH power brick and Zcontroller. I never use the smoke because I cannot handle the smell. I keep the smoke unit turned off.
Other engines all operate perfectly (Lionel conventional, my one Legacy diesel, and another MTH DCS Proto 2 engine). The Rudolph engine's sudden burst of acceleration/breaking to resume the original speed issue only happens on this one engine. It ran perfectly throughout the Christmas holiday (all December). This problem has only started last week when I decided to run the Rudolph engine.
I opened up the tender and engine to check for pinch wires. Everything checked out fine. I also gently cleaned the flywheel sensor in case something was obstructing its function. The situation continued.
Has anyone ever experienced this sort of problem? Could it be caused by a dying Protosound battery? I am planning to get a replacement battery this weekend to see if that solves the issue.
Any insight is much appreciated.
Thanks,
Terrence
