14
Appendix A: Service Information
One side is way louder than the other
• Are both Level controls set to the same position?
• Check your source signal to make sure the left
and right signals are balanced.
• Are the speaker impedances matched? Different
speaker loads can cause different volume levels
on each side.
• Try switching sides: Turn off the amp, swap the
speaker cables at the amp, turn the amp back
on. If the same side is still louder, the problem
is with your speaker cabling. If the other side is
louder now, the problem is with the mixer, the
amp, or the line-level cabling.
The stereo music sounds kind of
sideways, and the bass frequencies
diminish when standing center, but get
louder as you approach one side
• Check the polarity of the speaker cable
connections. You may have your positive and
negative reversed at one end of one speaker cable.
As soon as the music gets loud, the amp
shuts down
• Check the OL LEDs and make sure that they are
not lighting continuously. If they are, turn down the
signal source or the Level controls on the amp.
• Can the amp breathe? The amplifier draws
its ventilation air in from the back. It needs
plenty of fresh air to stay cool.
Do not block the
ventilation holes.
I hear thunder, even when the amplifier
is turned off
• It’s going to rain. Get inside quickly. Bring the
amplifier with you.
Poor sound
• Is it loud and distorted? Turn down the signal
coming from the mixer or signal source.
• Is the input connector plugged completely
into the jack? Check the speaker connections
and verify that all connections are tight and
that there are no stray strands of wire shorting
across the speaker terminals.
• If possible, listen to the signal source with
headphones plugged into the console. If it
sounds bad there, the problem is not in the
amplifier.
Warranty Service
Details concerning Warranty Service are spelled
out in the Warranty section on page 19.
If you think your amplifier has a problem, please
do everything you can to confirm it before calling
for service. Doing so might save you from the
deprivation of your amplifier and the associated
suffering.
These may sound obvious to you, but here are
some things you can check. Read on.
Troubleshooting
No Power
• Our favorite question: Is it plugged in? Make sure
the AC outlet is live (check with a tester or lamp).
• Our next favorite question: Is the POWER switch
on? If not, try turning it on.
• Is the red LED next to the POWER switch
illuminated? If not, make sure the AC outlet is
live. If so, refer to “No Sound” below.
• Has the BREAKER switch popped? Try pushing
in the BREAKER switch. If it pops out again right
away, refer to “Repair” on the next page.
• The AC fuse inside the amplifier is blown. This is
not a user-serviceable part. Refer to “Repair” on
the next page to find out how to proceed.
No Sound
• Are the channel Level controls turned up? Slowly
turn them up and see if you hear anything.
• Is the signal source turned up? Make sure the
signal level from the mixing console (or whatever
device immediately precedes the amplifier) is
high enough to produce sound in the amplifier.
The SIG LEDs should be blinking to indicate that
signal is present.
• If the speakers are wired for BRIDGE mode,
make sure the AMP MODE switch is set to
BRIDGE.
• If the amplifier has gotten extremely hot, the
thermal protection circuit may have activated.
Allow the amplifier to cool down and normal
operation should resume.
• Are there fuses in the speakers, or in-line fuses
in the speaker wire? Check ‘em to see if they’re
blown.
• Make sure the speakers are working properly.
