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Poor Bass response
• Check the polarity of the speaker cable connections. You may have your
positive and negative reversed at one end of one speaker cable.
• Make sure the Clip LEDs are not lighting continuously. If so, turn down the
signal source or the amp Level controls.
Noise/Hum
• Check the signal cable between the mixer and the amplifier. Make sure all
connections are good and sound.
• Make sure the signal cable is not routed near AC cables, power transformers,
or other EMI-inducing devices.
• Is there a light dimmer or other SCR-based device on the same AC circuit as
the amplifier? Use an AC line filter, or plug the amplifier into a different AC
circuit.
• If possible, listen to the signal source with headphones plugged into the
console. If it sounds noisy there, the problem is not in the amplifier.
• Is there a cable-TV audio feed in your system? An incorrect ground may
causes a "ground loop" hum.
• Sometimes it helps to plug all the audio equip-ment into the same AC circuit
so they share a common ground.
FAULT CHART
Fault Possible Reason
Check fuse in the primary (rear panel) and/or
No power
Check +/-12V supply on PSU.
High Bias: Check preset setting if it is disturbed.
Output devices are short, replace them
Bridge rectifiers have failed
Transformer is short/open
Filter capacitors on the power amp or PSU have gone bad.
DC on the output: Check bias setting or output device has failed.
±12V supply not present on the power amp board and/or
either of the ±LV & HV voltages not present and/or
Inter cabling from input to power amp PCB, Input to front control pcb, PSU to front
control pcb is not properly connected and/or
Amplifier Dead(high loading)
Output devices are short, replace the same.
Check fan by giving external 12V DC, it may be faulty if so replace it. Or ,
Check thermal switch loom and/or
Fan not working
Bridge rectifier (in the secondary AC1 & AC5) is faulty. Replace it.
Protect LED continues glow
DC on output or heatsink temperature is too high.
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