Phoenix Gold ZX475Ti - Manual (Page 20)

pg. 19
ZX Ti amp manual
TROUBLE-SHOOTING
SYMPTOM
No output and Power-on
LEDs are off
No output and power-on
LEDs are on
Distorted sound
Amplifier cuts off when
driven to high output
levels. Thermal protection
circuit activated (yellow
LED on).
POSSIBLE CAUSE
No battery, ground, or remote
connection
Blown or melted power fuse
No signal from the head unit or
previous signal processor
Faulty input signal cables
Faulty speaker or speaker cables
Clipped input signal feeding the
amplifier or signal processor
Amplifier or signal processor's input
sensitivity too high
Poor ventilation
Total speaker impedance is too low
causing excessive heat.
SOLUTION
Verify that the B+, B-, and remote turn-on
terminals are properly connected and that the
headunit is turned on. Use a DC voltmeter to
check for 12 volts between the ground terminal
and the B+ terminal. Also, check between the
ground terminal and the remote turn-on terminal.
Use an ohmmeter to verify that the fuse has
continuity between its ends. Disconnect the main
B+ cable from the battery and the inputs of all
devices in the system (including capacitors). Use
an ohmmeter to check for a short between the
power cable system and the vehicle's chassis.
Correct any short and install a new fuse. Replace
only with the same rating and type of fuse.
Use an AC voltmeter to check for voltage at the
headunit or processor's preamp outputs. The
level should fluctuate with peaks in the music.
An analog gauge works well for this test.
Use an AC voltmeter to check for voltage at the
signal cables' outputs. Try substituting different
signal cables.
Try substituting another speaker or cables.
Make sure the headunit and all other components
are not producing a clipped signal. Most head-
units clip their own output above 7/8 volume.
Distorted signals coming into the amp will sound
distorted at any input sensitivity setting.
Lower input sensitivity (counterclockwise).
Setting the sensitivity too high causes distortion.
Distortion causes speakers to rapidly overheat
and can result in speaker failure.
Check for a poor mounting location that allows
hot air to be re-circulated within the heatsink.
Check for blocked input or exhaust openings.
Re-wire speakers to raise the total impedance
seen by the amp. Minimum impedance is 2 ohms
bridged or 1 ohm stereo.