JBL GX-A422SI Service Manual ▷ View online
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TROUBLESHOOTING
If your amplifier isn't performing the way you think is should, check to see if the problem is covered in this section before calling your dealer or
contacting JBL customer service.
PROBLEM
CAUSES AND SOLUTIONS
No sound (the amplifier's Power LED is off)
• Check that the amplifier's +12V and GND connections have been properly made.
• Check if the fuse on the +12V wire located near the battery is blown: If so, replace it with an
identical fuse.
• Check all amplifier fuses; if any are blown, replace them with identical fuses.
• If you are using the amplifier's REM connection for turn-on, check that the wire is properly
connected to the audio system's remote turn-on wire or to the vehicle's ACC power terminal.
No sound (the amplifier's Power LED is orange)
• Check that all amplifier input and speaker connections have been properly made.
• Check that the amplifier's Level controls are not turned all the way down (counter-clockwise).
• Check that the vehicle audio system's source unit's volume control is not turned all the way
down.
No sound (the amplifier's Protection LED is red)
• Confirm that the vehicle's electrical system is supplying between 9V and 16V DC to the
amplifier. If the supply voltage is outside of this range, correct the condition before attempting
to use the amplifier.
• If the amplifier has overheated, wait until it has cooled down before attempting to use it again.
• Disconnect all speakers from the amplifier and attempt to turn it on again:
– If the amplifier turns on (the Power LED is orange), there is a short circuit in one or more of
the speaker wires. Correct all short circuits before reconnecting the speakers to the amplifier.
– If the amplifier does not turn on (the Protection LED is still red and the Power LED is off),
contact your authorized JBL dealer for assistance.
www.jbl.com
Engli
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PROBLEM
CAUSES AND SOLUTIONS
Sound only comes from some of the speakers
connected to the amplifier
• Check that the vehicle audio system's source unit's balance and fader controls are set to their
center (midpoint) positions.
Sound is too quiet, even with the vehicle audio
system's source unit volume all the way up
• Check that the amplifier's Level controls are not turned too low. See Set The Input Level, on
page 11, for information about setting the Level controls.
Sound in the subwoofer is distorted
• Set the Bass Boost switch to "OFF."
• Check that the distortion is not originating from the vehicle audio system's source unit.
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SPECIFICATIONS
GX-A422SI
Peak power
600W
Rated power output @ 4 ohms
40W x 2
Bridged power output (4 ohms, 1% THD)
110W x 1
THD+N at rated power
<1%
Signal-to-noise ratio (rated output @ 4 ohms)
>93dB
Effective damping factor (4 ohms)
>50
Frequency response (±1dB)
20Hz – 20kHz ±1dB
Maximum input voltage
20V
Maximum input sensitivity
200mV
Fuse size
20 A
Dimensions (H x W x D)
2" x 8-1/8" x 6-13/16" (51mm x 206mm x 173mm)
Weight
3.1 lb (1.4kg)
1
2
3
4
power supply
1
2
3
GROUND
REM
+12V
bass boost
45Hz 0-12dB
power
P1
A5
FUSE
P2
HI-IN auto ON
A1
A2
PRT
INPUT SENS
0.2V-4V
A1
A2
A3
A4
LP
FLAT
A6
L -out
2Ω/4Ω
2Ω/4Ω
L input
Class AB Audio Power Amplifier
input selector
variable crossover
1
2
3
4
HI IN
Pitch 2.5mm
A
bass boost
45Hz 0-12dB
B5
INPUT SENS
0.2V-4V
crossover
80Hz 12dB/ oct
B1
B2
B3
HP/LP pass
B4
LP
FLAT
B6
4R +out
2Ω/4Ω
2Ω/4Ω
R input
Class AB Audio Power Amplifier
input selector
variable crossover
A
A1
A2
3
2
1
4
A
7
6
5
8
B
HP
HP
10Hz
80Hz
＞
40KHz
crossover
80Hz 12dB/ oct
HP/LP pass
10Hz
80Hz
＞
40KHz
SET BLOCK DIAGRAM
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