As my reply from Lionel seems to state I have few options
Douglas,
There is not a way to repair the CW80. We do not have a tool to open them, as when they are in warranty - we simply replace them. We do not make repairs on CW80's. At this point, you may want to consider purchasing a new transformer.
Meghan
Lead Customer Service Representative
6000 Victory Lane| Concord, NC 28027
1-800-4LIONEL | 704-455-8940 (f)