I have two MTH Tinplate Traditions 400e PS2 engines. They are great! Two things to consider:
On the PS2 engine, the can motor is in a standard bild-a-loco frame. The collector plate on the bottom is held on by two thumb screws, one on each end. Sometimes that plate gets a little loose. There is no wire from the collector plate to the motor. It is a friction contact. Try removing and reinstalling the collector plate and check it for any damage in the process. I have had a problem where the collector plate looks to be installed correctly, but it is shorting somehow. A small adjustment made the engine come alive. You should also clean and oil the rollers. I make a cradle for the engine when I turn it upside down. A box filled with foam or a pillow can work. Make sure it is secure and won't tip over and fall.
Second, make sure your battery is fully charged. If the engine dies without going through a full shutdown sound sequence, it needs to be charged. you should charge it for at least 7 hours to get half a charge. Don't charge it all the way if you are planning to store the engine for a long time. The batteries are best stored at half charge.
Let us know how it goes.
George
