I helped a school to purchase six XD-V35L units.
Upon receipt, I checked all six for functionality. 5 of the six sound great.
The 6th powers up just fine, shows receipt of signal from the microphone, but the receiver does not receive a signal. I have tested the other transmitter units on the same receiver and the receiver is clearly fine. I also have tried different lavalier mics, though it was obvious that the mic was sending a signal to the transmitter.