Sennheiser SK 5012 Notice D'emploi page 35

If problems occur ...
Insert the batteries properly into the battery compartment.
Check the polarity (+/-) of the batteries.
Check the battery status.
Turn the transmitter and the receiver on.
Set the transmitter and the receiver to the same frequency.
Make sure that the receiving antenna is within the transmitter's
range.
Make sure that neither transmitting nor receiving antenna are
shielded by metal constructions (or metallic clothing).
Make sure that the receiving antenna is not in direct contact with the
skin.
If the problem persists, please contact your specialist dealer for assi-
stance.
Never open the unit!
SK 5012 - 35