Basic Troubleshooting - JBL 1201.1 Service Manual

INSTALLATION AND SETUP
Figure 13. Installing neon tubes in a JBL GTO amplifier.
TROUBLESHOOTING
SYMPTOM LIKELY CAUSE
No audio No voltage at BATT+
(POWER LED or REM terminals,
is off) or bad or no ground
connection
No audio DC voltage on
(PROTECT LED amplifier output
flashes every
4 seconds)
No audio Amplifier is
(PROTECT overheated
LED is on)
No audio Voltage less than 9V on
(PROTECT BATT+ connection
and POWER
LEDs flash)
To Neon
Power
Supply
To Neon
Power
Supply
SOLUTION SYMPTOM
Check voltages at No audio
amplifier terminals (PROTECT
with VOM LED is on)
Amplifier may need Distorted audio
service; see enclosed
warranty card for
service information
Make sure amplifier Distorted audio
cooling is not blocked and PROTECT
at mounting location; LED flashes
verify speaker system
impedance is within
Music lacks
specified limits (see
"punch"
"Specifications" on
the next page)
Check vehicle
charging system for
defective voltage
regulator
6
GTO 1201.1/1201.1II
LIKELY CAUSE SOLUTION
Voltage more than 16V Check vehicle
or less than 8.5V on charging system for
BATT+ connection defective voltage
regulator
Input sensitivity is Check INPUT
not set properly, or LEVEL setting; or
amplifier or source check speaker wires
unit is defective for shorts or grounds
Short circuit in Remove speaker leads
speaker or wire one at a time to locate
shorted speaker or
wire, then repair
Speakers are not Check speaker
connected properly connections for
proper polarity