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8.0 E-4 System Troubleshooting
8.2.3 Amplifier fault
The AMP OUTPUT LEDs work in pairs (1 and 2, 3 and 4) and indi-
cate the operating status of the four amplifier output channels.
When an amplifier fault occurs, the amplifier mutes its outputs
and indicates an error. After a short period of time the amplifier
will try to operate again. If the fault condition persists, the ampli-
fier will attempt to restart six times, after which it will remain
muted.
Amplifier faults are typically caused by a shorted speaker line, an
overdriven amplifier, or a saturated output transformer.
• To check for a shorted speaker line, remove the speaker con-
nection from the amplifier channel. If this resolves the problem,
locate and correct the shorted loudspeaker line.
• To make sure that you are not overdriving the E-4 output,
change to a different source. If the problem no longer exists,
use the
Installer
™ software to reduce the input level of the
original source that was overdriving the output.
• To make sure an output transformer is not being saturated,
check to see if the correct speaker EQ setting is selected.
If none of these actions solve the problem, read the instructions
in the following flow chart or check the error log using the
Installer
™ software.
AMP OUTPUTS
1
2
3
4
SYSTEM
STATUS
AUDIO SOURCES
1
2
3
4
DIRECT
INPUT
STANDBY
Check for
• Shorted wiring
• Overdriven amplifier
(reduce output gain)
• Transformer saturation
• Entry in
Installer
™ soft-
ware error log
AMP OUTPUT
indicators are red
Has the E-4 unit
shut down during
operation?
• Check the number of loudspeak-
ers connected to the E-4 unit.
Verify that the total sum of loud-
speaker taps connected to the
E-4 unit does not exceed 400W.
• Verify that there are no shorts on
the speaker output lines.
No
Yes
• Switch POWER to OFF.
• Disconnect the load and switch
POWER to ON.
• Verify that there are no shorts on
the speaker output lines.
See amplifier fault troubleshooting
section for course of action.
Is SYSTEM
STATUS indicator
green?
Does the
Installer
™
software Error Log list
any amplifier
faults?
Contact Bose
Customer Service.
Yes
No
No
Yes