Hmmm... The situation you are experiencing sounds very similar to what happened to me. I received a brand new Legacy 990 set and hooked it up properly as per the instructions. My engines would start up and run sporatically, then they eventually would not operate at all (it happened within a day).
It turned out that the velocity dial on the remote had failed. I had to ship the 990 to Lionel for repair. Lionel fixed it very quickly and shipped it back to me. Now it works pefectly.
I am not saying you have a bad velocity dial, but it does sound like the unit needs to be repaired. To get a free repair, you need to call Lionel and speak with the service department. They will attempt to troubleshoot and diagnose the issue you are having over the phone. If they cannot talk you through it and get your system working, they will issue a return authorization number and you will have to ship it to Lionel.
Yes, returning a new Legacy 990 unit to Lionel to be repaired is a pain in the smokestack, but in the end, it will be well worth it.
Your other altenative is to contact the seller. Some hobby shops have simply replaced malfunctioning 990s with new ones. My hobby shop made me send my system to Lionel.
