Manual

ENGLISH

AMPLIFIER ACTIVATES THE PROTECTIVE CIRCUIT / THE PROTECT LED LIGHTS UP

Check the following steps:

Short circuit on the speaker cables

• First disconnect all speaker cables from the amplier. Use a multimeter to check the ohmic impedance

of each loudspeaker by measuring between its plus and minus lines. With standard loudspeakers the

value uctuates between 3 and 5 ohms. The values for low-resistance subwoofers can be lower.

• The measurement shows a resistance value of less than 0.5 Ohms

Then there is a short circuit. Remove the wiring of the affected loudspeaker at its connections. Now

use the multimeter to check the ohmic impedance directly at the loudspeaker connections by measur-

ing between the plus and minus connections.

The measurement shows a resistance value of more than 0.5 Ohms

• The speaker is ne, so the speaker wire appears to be defective and causing a short circuit.

Replace the defective speaker cable.

The measurement shows a resistance value of less than 0.5 Ohms

• The speaker appears to be defective and is shorting out. Replace the defective speaker.

The load impedance of the loudspeakers or the subwoofer is too low

• Compare the ohmic impedance of the connected loudspeaker or subwoofer with the technical speci-

cations of the amplier. For example, if the amplier is only designed for 2 or 4 ohm operation, no

loudspeaker with less than 2 ohms may be connected.

The cross-section of the power cables is too small

• If the cable cross-section is too small, this leads to an increased ohmic resistance and thus to a volt-

age drop (voltage loss). This indicates that the amplier consumes more power. The increased power

consumption results in a signicantly higher heat development and the amplier switches to thermal

protection mode. Therefore, observe the recommended cable cross-sections in these instructions and, if

necessary, lay power cables with a larger cable cross-section.

The amplier is overheated

• The heat sink of each amplier requires sufcient air circulation to be able to dissipate the heat gener-

ated during operation. If necessary, change the installation position in favor of better cooling of the

amplier or ensure better air circulation at the installation location.

• Turn off the sound system and wait about half an hour for the amplier to cool down again. With very

hot outside temperatures and strong sunlight, enormous heat develops inside the vehicle. The amplier

then activates its thermal protection circuit to prevent damage. After cooling down, the amplier works

properly again.

All instructions in this trouble shooting refer to the entire sound system and its individual compo-

nents. The features of your device may not match the functions described in the notes. Then skip

this point and move on to the next one.

CAUTION