For about a week I noticed that my 18 volt magic bulb was dimming on my layout. The other day I checked the track voltage and it was about 15.9 or so which seems low. So I checked the connectors from the power supply brick into the TIU and found that the plastic had melted on the Fixed Voltage IN 1 black terminal banana plug. I figured it was a loose connection and fixed it but no improvement in voltage and the terminal gets very hot to the touch. Trains are on the track but not operating. I tried three different transformers and get the same thing. Also does not appear to be track related. Next step is to open the TIU and see if the connection is loose on the inside. Right now that's all I can come up with. Poor contact resistance would cause a voltage drop and result in heat generation? Maybe a bad fuse?
Thanks for any help.