JBL GTO5355 SETTINGS TROUBLESHOOTING AND SCHEMATIC DIAGRAM

JBL GTO5355 Settings troubleshooting and schematic diagram

Category: Car audio Repair 

Contents of this article 

• Setting the amplifier 
• Troubleshooting 
• Schematic diagram 

JBL GTO5355

Specifications
# 55W RMS x 4 channels, plus 225W RMS x 1 channel, @ 4 ohms and ≤1% THD + N*
# 75W RMS x 4 channels, plus 360W RMS x 1 channel, @ 2 ohms and ≤1% THD + N*
# THD + N: 0.03% (rated power @ 4 ohms)
# Signal-to-noise ratio: 85dBA  (reference 1W into 4 ohms)*
# Signal-to-noise ratio: 104dBA  (reference rated power into 4 ohms)
# Frequency response: 10Hz – 83kHz and  20Hz – 250Hz
# Max power: 660 watts
* CEA-2006A-compliant
1. Speaker Output Connectors
# Connect the speakers to these terminals, observing proper polarity.
# Five-channel operation: Connect the front left speaker to the Front L+ and L– terminals and the front right speaker to the Front R+ and  R– terminals. Repeat for the rear speakers, using the Rear L+ and L– terminals, and  the Rear R+ and R– terminals. Connect the  subwoofer to the Sub+ and Sub– terminals.
# Four-channel operation: Connect the stereo speakers to the Front terminals, as above. Connect the single speaker into which the amplifier’s rear channels will be bridged to the Rear R+ and Rear L– terminals. Connect the subwoofer to the Sub+ and Sub– terminals
# Three-channel (bridged) operation: Connect one speaker to the Front R+ and Front L–  terminals. Connect the other speaker to the Rear R+ and Rear L– terminals. Connect the subwoofer to the Sub+ and Sub– terminals.
# Minimum speaker impedance for stereo  operation is 2 ohms. Minimum speaker  impedance for bridged operation is 4 ohms. Minimum subwoofer impedance is 2 ohms.
2. Fuses
# Replace only with same type and rating.
3. Power Input Connectors
# +12V: Connect to the positive terminal of the vehicle’s battery. 4 AWG wire is recommended. Install an appropriate fuse holder and fuse (80A minimum) within 18 inches of the battery. Make sure the wire is not damaged or pinched during installation. Install protective grommets when routing wires through the firewall or other sheet metal.

# REM: Connect to the “Remote Out” lead from the source unit or to a source of switched  12V+ (ACC).
4. Front Input Connectors (RCA)
# Connect to the front RCA outputs from the source unit or signal processor.
5. Front Input-Level Control
# Used to match the front input level of the  amplifier to the output level of the source unit.
6. Front Crossover-Frequency Control
# 12dB/octave crossover, variable from  32Hz to 320Hz.
# See K for the adjustment procedure.
7 Front Crossover-Filter Selector
# LPF: Select for subwoofer(s).
# FLAT: Select for full-range speakers when  no subwoofer will be used in the system.
# HPF: Select for midrange speakers or  full-range speakers when a subwoofer is  used in the system.
8. Power On LED
# Illuminated when the amplifier is on.
9. Subwoofer Input Connector (RCA)
# Connect to the subwoofer RCA outputs from  the source unit, or signal processor.
10. Rear Crossover-Filter Selector
# LPF: Select for subwoofer(s).
# FLAT: Select for full-range speakers when  no subwoofer will be used in the system.
# HPF: Select for midrange speakers or  full-range speakers when a subwoofer is  used in the system.
A. Rear Crossover-Frequency Control
# 12dB/octave crossover, variable from  32Hz to 320Hz.
B. Rear Input-Level Control
# Used to match the rear input of the amplifier to the output of the source unit.
C. Rear Input Connectors (RCA)
# Connect to rear RCA outputs from the source unit, or signal processor.
D. EXT/INT Switch
# If the source unit has a subwoofer output and you have connected it to the SUB input, set this switch to the EXT position. Otherwise, set it in the INT position.
E Subwoofer Remote Level Control Connector
# Connect the Remote Level Control (RLC) here, using the supplied RJ-11 cable.
F. Subwoofer Level Control
# Used to match the SUB input of the amplifier to the output of the source unit.
G. Protect LED
• Illuminated under any of the following fault  conditions: battery over/under voltage, short  circuit in speaker wires, amplifier is too hot, amplifier’s output circuit has failed (DC voltage present in the amplifier’s output).
H. Subwoofer Low-Pass Filter Frequency Control
• 12dB/octave low-pass filter, variable from 20Hz to 200Hz.

Troubleshooting
1. Status LED on Amplifier not Lit - Head Unit (Source) Turned ON
Verify:
A. Remote turn-on wire from source to amplifier has proper voltage
B. Power (B+) connections at amplifier, terminal blocks, and battery are secure
C. Ground (GND) connections at amplifier and vehicle chassis are secure
D. Battery B+ fuse (if used) is OK
E. Amplifier fuse is OK
F. B+ at battery and B+ at amplifier has proper voltage
2. Status LED’s Lit, No Output from Speakers in Normal Operating Condition
Verify:
A. RCA cables from amplifier to source are securely connected
B. Volume adjustment on amplifier is correctly adjusted
C. Source is ON and playing
3. Engine Noise From Speaker
Turn source OFF, Disconnect RCA cables at amplifier. If noise stops, check equipment & cables leading to amplifier.
Verify:
A. RCA cables are of good quality with no breakage to internal shields
B. RCA cables from source to amplifier are not run alongside any power cables
4. Amplifier Output Distorted Music
Verify:
A. Source output music to amplifier is not distorted
B. Source output sensitivity is correctly adjusted
5. Amplifier Shuts Down, Green LED’s are Lit - Amplifier is in Thermal Protection Mode
Verify:
A. Amplifier is mounted with adequate air circulation around heatsinks or vents
B. Amplifier is not mounted under carpet or sealed enclosure
C. Speakers meet correct impedance for application (mono or stereo hookup)
6. Amplifier Does Not Turn ON, and Red LED is Lit Amplifier (and not Connected to a Shorted Speaker)
Verify:
A. Speaker crossover (if used) is not defective

SCHEMATIC DIAGRAM 

POWER SUPPLY BOARS 

Using IC TL494

POWER AMPLIFIER 

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