Sunfire TGA-7200 - Manual (Page 16)

User's Manual
16
APPENDIX
The Sunfi re Amplifi er is expertly
designed and built to provide years of
trouble-free per for mance. Most prob-
lems that occur can usually be solved
by checking your setup or making
sure that the audio and video com-
ponents connected to your pro ces sor
are on and fully op er a tion al.
The following information will help
you deal with com mon setup problems
you may experience during normal
use of your unit. If the problems still
persist, please contact your Sunfi re
Dealer for assistance.
No sound from one or
more speakers
• Speaker cables may have come
undone. Turn off your system and
check the cables, and tighten the
amplifi er and speaker binding
posts.
• Broken audio cable.
• The preamplifi er volume level is
low for the chan nels concerned.
Recheck the pream pli fi er calibra-
tion procedure.
• A preamplifi er Mute switch may be
on, or an external processor loop
or a tape monitor loop is engaged.
• Check that your preamplifi er or
source is running the correct sur-
round sound mode. Maybe it is set
for stereo when you were expect-
ing 5.1 surround sound.
• Check in case any missing chan-
nels have been turned off in a
preamplifi er setup menu. For
example, the center amplifi er
channel will not receive a signal
if the preamplifi er has been set to
"Phantom."
• The Auto/on/off switch might be in
the off position.
• One of the fuses for the current
source outputs may have blown.
The amplifi er shuts down
often or the line fuse blows
often
• Check that the positive and nega-
tive speaker wires are not shorted
together.
• Make sure that no speakers are
shorted internally. If you have an
ohm-meter, disconnect the speaker
wires and mea sure the re sis tance
be tween the speaker’s positive
and negative terminals. If the read-
ing is less than 2 ohms, the speak-
ers may have an internal short.
Measure all speak ers and check
their impedance spec i fi ca tions.
• If you have connected speakers
in Par al lel, the overall impedance
may be too low. It is recommended
that you rearrange the speakers
in Series to increase the overall
im ped ance, thus taking some of
the load off the amplifi er.
• Make sure that the amplifi er
has good ventilation and is not
overheating. If the amplifi er is in
a closed rack, open up the rear
panel or use a quiet fan for im-
proved ventilation.
A hum is heard in your
speak ers
This problem is more than likely
caused by a “ground loop” in your sys-
tem, rather than a fault in the amplifi er.
Follow these steps to isolate the main
cause of the hum; there may even be
more than one.
• If your preamplifi er has XLR bal-
anced outputs, use them because
they offer greater immunity to
noise fi elds.
• Remember to unplug all compo-
nents in your system, including
the amplifi er, before disconnecting
or con nect ing any cables during
troubleshooting.
Troubleshooting Guide
• Try to have all of your equip ment
on the same electrical outlet or
circuit. Group all the low power
components (preamp, CD player,
DVD etc.) on a single outlet or
power strip. This is provided that
the overall current draw from your
equipment does not exceed the
rating of the outlet or breaker.
• Disconnect all cables which come
from outside the room, and check
if the hum goes away. This in-
cludes such connections as cable
TV, satellite TV, or roof top an-
tennas. Make sure that they are
dis con nect ed where they fi rst enter
the room, so they are making no
con nec tion to the preamplifi er or
the TV, or any other component. If
the hum is caused by the cable TV
line, then you will need a “ground
loop iso la tor.” This is an inexpen-
sive device fi tted in line with the
coaxial cable feed. Con tact your
ca ble com pa ny or your Sun fi re
Dealer for as sis tance.
• Disconnect all connections from
the preamplifi er to your TV, VCR or
DVD.
• As a test, disconnect any other
com po nent which has a ground ed
pow er cord.
NOTE: Never remove the
ground pin from any power
cords. This is very dan-
ger ous.
• If the hum persists, disconnect all
the source com po nents one at a
time from the back of the preampli-
fi er, until you identify the prob lem.
• Ground loop isolators are available
for audio lines and video. You can
ask your Sunfi re Dealer for assis-
tance.
• Try moving the speaker cables
away from any power cords. Try
just one speaker, connecting it to
each amplifi er channel and see if
one channel is bad.