QSC Audio CX168 user manual Operation Led Indicators, LED Indicators, Fully illuminated on normal

OPERATION: LED INDICATORS

LED Indicators

The LED indicators provide basic operation information to the operator. The ‘nor- mal’ indications of the LED’s are shown, below. NOTE! The BRDG and PAR mode indicator LED’s are discussed on page 9.

POWER: The power ‘on’ indicator LED is located at the upper-left of the gain control cluster. It is green and illuminates when the power switch is set to the on position and AC power is present at the IEC cord receptacle.

Normal indication: at power-on the LED will illumi- nate.

If no indication: Check AC power cord, AC mains, and that the DataPort is not being used to force the amplifier into ‘Standby’ mode.

When power is switched off: the LED may take several seconds to extinguish (go out); this is normal.

SIGNAL: Each channel has a green ‘signal’ LED located to the right of its gain control. The ‘signal’ LED lights up when the input signal is sufficiently strong.

Normal indication: illuminates when the input signal is present and sufficiently strong.

If no indication: check gain settings, input cables, connections and audio source. If audio source is extremely low signal strength, signal LED may not illuminate; this is normal but indicates that the input signal strength should be increased.

Occasional illumination: normal for weak input signal strength.

Fully illuminated (on): normal.

CLIP : Each channel has a red ‘clip’ LED that illumi- nates when the channel clips. It is located to the upper- right of each channel’s gain control.

Normal indication: illuminates briefly at extreme output power peaks. Occasional clipping at high power levels may be normal. At power-on, the clip LEDs may briefly flash during turn-on muting.

Continuous operation at high power may trigger the thermal protection circuitry, shutting down the amplifier and fully illuminating the clip LED. Operation will resume after the amplifier has cooled down sufficiently.

If no indication: normal if the amplifier is operated at nominal output levels. If the input signal is weak, it may not be capable of driving the amplifier into clipping, even at full gain.

Occasional illumination: Occasional clipping (once briefly every few seconds) when operation at high power levels does not indicate trouble. Continuous operation at high power may trigger the thermal protection circuitry, shutting down the amplifier and fully illuminating the clip LED.

Illuminated most of the time: Not normal; for cleaner sound, reduce the output of the amplifier and/or input signal to avoid thermal shutdown of the amplifier and possible speaker damage. If clipping persists at normal levels, check for shorted or abnormal load impedances.

Fully illuminated (on): Amplifier is in thermal shut down. Reduce gain settings or input signal and allow the amp to cool down. Leave the power on so that the fan continues to run; operation will automatically resume after the amplifier has cooled sufficiently.

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