[. . . ] Assemble the device in such a way that the available ventilation openings are not covered. Should the device become damaged, in particular the mains supply cable, do not operate the device any longer, but rather have it repaired by an expert. For safety reasons a broken or damaged mains lead may only be replaced by an equivalent lead from the manufacturer, our customer service department or a similary qualified person. [. . . ] The power LED (10) then lights up in red and shows the operating status. If the input signal is very quiet or switched off, the transmitter will switch off automatically after approx. 5V into the battery compartment of the headphones (batteries not supplied). Please ensure that the polarity is correct (see the floor of the battery compartment or the inscription on the outside)!If the device is not used for a long period of time, remove the batteries to avoid the spilling of battery acid. Turn the channel selector switch until the channel diode shows the best possible reception by means of the green light. If there is interference to the reception of the headphones, you can change the transmission frequency by switching the channels. With the switch (12) on the bottom of the transmitter it is possible to set 3 different channels. Once you have set a different transmission frequency, turn the channel selector (4) until the green light of the channel diode shows you the best possible reception. Please ensure the correct polarity as shown on the bottom of the battery compartment. When using the device for the first time, the batteries should be charged for a period of 12 hours. ⷠBefore charging it is important to make sure that only rechargeable batteries are inserted. It is not technically possible to charge batteries that are not rechargeable, and any attempt to do so can damage the device!Poor or fuzzy sound · Turn the channel selector switch (4) again to look for the best reception. There may be interference from other radio emitting equipment such as cordless telephones, mobile telephones or CB radio. Is the sound source switched on and is a sound signal being transmitted? [. . . ] *) Damage to accessories does not mean automatic free replacement of the whole machine. Broken glass or breakage of plastic parts are always subject to a charge. Motor pistons, kneading blades, drive shafts, spare remote control, spare toothbrushes, saw blades, etc. [. . . ]