Trouble Shooting - Field Acoustics UK 500 Instruction Manual

6. TROUBLE SHOOTING.

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(1) ALWAYS:
Ensure the amplifier has no less than 4 Ohms worth of loading across each
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channel for Stereo/Mono modes.
Ensure Bridge Mode (if used) is wired correctly (see chapters 4.2 and 5.2) and is
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loaded with no less than 8 Ohms.
Ensure wiring is safe and correct.
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(2) NORMAL ARTEFACTS:
When heavily driven, the amplifier itself may make a noticeable hissing sound in relation to the
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supplied signal. This is a normal phenomenon relating to the behavior of certain components which
vibrate slightly under the high powers involved.
The Fans on this Series may appear to generate more noise than earlier models, they run at higher
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speeds to increase the cooling efficiency of the amplifiers. They will also increase their speed when
the amplifier is under load.
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(3) THE POWER LIGHTS DO NOT ILLUMINATE
1. Check that the mains supply is turned on.
2. Check that the mains switch is turned on.
3. Check internal fuse. Replace if blown.
(same type of fuse specified/installed must be used, do not change)
4. If fuse re-blows refer to service personnel.
5. If fuse has not blown, but the amplifier still malfunctions, refer to service personnel.
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(4) THE AMPLIFIER IS WORKING, BUT OUTPUT VOLUME IS LOW
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Check the signal from the input source and signal cables. The amplifiers are designed to operate at
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an input voltage of 1.2V. If the signal source is below this refer to qualified service personnel for a
minor modification.
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(5) AMP OUTPUT LEVEL INDICATORS ARE WORKING, BUT NO SOUND IS COMING OUT
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Check Speakon connectors are securely attached.
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(The amplifier must be operating if the output level indicators are working)
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(6) THE AMPLIFIER IS GIVING A LOWER OUTPUT THAN NORMAL, WITH DISTORTION
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The protection circuits (current clamps) are operating. Check all leads for short-circuits. Try
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another set of leads and loudspeakers.
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(7) THE AMPLIFIER IS OVERHEATING
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Check that the fan is not obstructed with debris, and is rotating freely.
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Check speaker leads for short circuits.
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Check to see that amplifier output 'negatives' have -not- been connected together in bundled cable
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looms - especially in bridge mode
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If any of these, or other symptoms persist, Please contact us with the details below for help,
advice and service:
Contact Details:
If the amplifier is to be shipped, use factory packaging or other secure method as transit
damage is not covered by the warranty.
Address:
FIELD ACOUSTICS,
Distributed by Lamba plc
Unit 1
Southfields Road
Dunstable
Bedfordshire
United Kingdom
LU6 3EJ