Phoenix Gold ZX475Ti - Manual (Page 21)

pg. 20
ZX Ti amp manual
Authorized Phoenix Gold Service Centers
USA
Phoenix Gold Factory
877.745.3782
Canada
Trends Electronics
604.988.2966
TROUBLE-SHOOTING
SYMPTOM
Amplifier cuts off when
driven to high output
levels. Overload circuit
activated (red LED on).
POSSIBLE CAUSE
Excessive output current is the only
thing that can cause the Overload
LED to light. There are only a few
possible causes:
A damaged speaker cable touching
the vehicle chassis, speaker cables or
speaker tinsel leads touching each
other, or damaged speaker voice coil.
Damaged passive crossover
components.
Total speaker impedance is too low
causing excessive output current.
Defective output transistor inside the
amplifier
SOLUTION
With the speaker wires disconnected from the
amp, use an ohmmeter to check for a short from
any speaker cable to chassis ground. Check the
DC resistance of the speaker's voice coil. It
should be close to the speaker's nominal imped-
ance specification and should fluctuate when the
cone is touched. Visually check each speaker for
damaged tinsel leads, or other broken parts.
Smell the speaker's magnet area for a burned
scent indicating a damaged voice coil.
Visually examine inductors, capacitors and
resistors for signs of heat stress, water, or
physical damage. Use a soldering iron to touch
up connections to the crossover circuit board.
Try substituting a different crossover network.
Re-wire speakers to raise the total impedance
seen by the amp.
This condition will cause the overload LED to
stay lit without speaker wires connected to the
amplifier. The amplifier must be returned to an
authorized service center for repair.