Sunfire TGA7401 User Manual

Page of 20
User's Manual
16
APPENDIX
The Sunfire Amplifier is expertly 
designed and built to provide years of 
trouble-free performance. 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 processor 
are on and fully operational.
The following information will help 
you deal with common setup problems 
you may experience during normal 
use of your unit. If the problems still 
persist, please contact your Sunfire 
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 
amplifier and speaker binding 
posts.
•  Broken audio cable.
•   The preamplifier volume level is 
low for the channels concerned. 
Recheck the preamplifier calibra-
tion procedure.
•   A preamplifier Mute switch may be 
on, or an external processor loop 
or a tape monitor loop is engaged.
•  Check that your preamplifier 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 
preamplifier setup menu. For 
example, the center amplifier 
channel will not receive a signal 
if the preamplifier 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 amplifier 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 measure the resistance 
between 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 speakers and check 
their impedance specifications.
•  If you have connected speakers 
in Parallel, the overall impedance 
may be too low. It is recommended 
that you rearrange the speakers 
in Series to increase the overall 
impedance, thus taking some of 
the load off the amplifier.
•  Make sure that the amplifier 
has good ventilation and is not 
overheating. If the amplifier 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 
speakers
This problem is more than likely 
caused by a “ground loop” in your sys-
tem, rather than a fault in the amplifier. 
Follow these steps to isolate the main 
cause of the hum; there may even be 
more than one.
•  If your preamplifier has XLR bal-
anced outputs, use them because 
they offer greater immunity to 
noise fields.
•   Remember to unplug all compo-
nents in your system, including 
the amplifier, before disconnecting 
or connecting any cables during 
troubleshooting.
Troubleshooting Guide
•  Try to have all of your equipment 
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 
disconnected where they first enter 
the room, so they are making no 
connection to the preamplifier or 
the TV, or any other component. If 
the hum is caused by the cable TV 
line, then you will need a “ground 
loop isolator.” This is an inexpen-
sive device fitted in line with the 
coaxial cable feed. Contact your 
cable company or your Sunfire 
Dealer for assistance.
•   Disconnect all connections from 
the preamplifier to your TV, VCR or 
DVD.
•  As a test, disconnect any other 
component which has a grounded 
power cord.
NOTE: Never remove the 
ground pin from any power 
cords. This is very dan-
gerous.
•  If the hum persists, disconnect all 
the source components one at a 
time from the back of the preampli-
fier, until you identify the problem.
•  Ground loop isolators are available 
for audio lines and video. You can 
ask your Sunfire Dealer for assis-
tance.
•  Try moving the speaker cables 
away from any power cords. Try 
just one speaker, connecting it to 
each amplifier channel and see if 
one channel is bad.