Hall Research HR-101-S - Manual (Page 6)

MIC Preamp/Audio over Single Fiber
6
5.0 Troubleshooting
Make sure that all of the connections to the units are solid, and check the
state of the PWR LED’s on the front. Do not open or try to repair the unit
yourself. There is no customer repairable item in the device and you will
void your warranty.
Contact HR Support at 714-641-6607 or via email or web. If you need to
ship your unit for repair, make sure to get a Return Material Authorization
(RMA) number first.
When returning a unit for repair, make sure to include a detailed
description of the setup and failure.