beautypg.com

Troubleshooting – Bogen M-CLASS AMPLIFIER M450 User Manual

Page 17

background image

Troubleshooting

1

4

• Amplifier not plugged in.
• AC outlet dead.
• Power switch off.
• Breaker (power switch) tripped.

- Turn off, then turn back on.

• 70V mono connections on amplifier incorrect.
• Poor/broken speaker wiring.
• Defective speakers.

• Poor electrical connections at input.
• Input cable routed near AC cables, power transformer, or

other EMI radiating devices.

• Electrically noisy devices operating on the same AC circuit.
• Poor equipment grounding.

- Ensure that all AC safety grounds are connected.
- Make sure that all components in audio chain are tied to the
same ground.

NO SOUND

NOISE/HUM

PROBLEM

CONDITION

CAUSE

DISTORTED

SOUND

Status LED is off.

INTERMITTENT

OPERATION

Status LED is green.
Signal LED is off.

• Level controls turned down.
• No signal from source.
• Input module jumpers in wrong bus configuration (if available).

Status LED is green.
Signal LED is green.
Clip/Limit LED is off.

Status LED is green.
Signal LED is green.
Clip/Limit LED is off.

• Input signal level too high.
• Poor speaker connections.
• Lo-cut switch set to Flat (70V mono system only).

POOR

LOW-FREQ.
RESPONSE

(NO BASS)

Status LED is green.
Signal LED is green.
Clip/Limit LED is off.

• Lo-cut switch setting.
• Speaker wiring phasing.
• Module bass control setting (if available).

Status LED is red/green cycling.

• DC level at signal input.
• Load impedance too low.
• Amplifier speaker output is short-circuited.
• Amplifier too hot (check for proper ventilation clearances).

Status LED is green.
Signal LED is green.

This manual is related to the following products: