might a fried the RX the Teu does NOT have a BEC built in, and an external is needed for 90% or so of current radios (some old ones are fine that have BEC's in the receivers)
any 3A helicopter BEC will work fine, If you get one you plug the BEC into the battery slot on the RX, and have to make sure to disconnect the red(or middle if it uses one of the other color schemes) wire on the 3 pin harness from the ESC that goes in channel 2. One of our members had a similar issue with his TEU in his buggy, and the issue went away after he got the BEC(and a new RX seeing his was toasted).

As for the motor there is no right or wrong way to plug it in.