Symptom

Diagnosis

 

Remedy

 

 

 

 

 

 

Speaker Output

Input gain signal

for

Readjust input gains of

 

Low or Distorted

amplifier is incorrectly

amplifier.

 

 

set.

 

 

 

 

 

 

 

 

 

Source unit output too

Check system with known

 

 

low or source unit has

working source and repair

 

 

no output.

 

or replace original source

 

 

 

 

 

as needed.

 

 

 

 

 

 

XCard is missing or not

Check XCard position and

 

 

placed properly in cross-

repair or replace as neces-

 

 

over slots.

 

sary.

 

 

 

 

 

 

Low battery voltage or

Check the alternator, bat-

 

 

large voltage drops

to

tery, fuse, and power and

 

 

the amplifier under load.

ground wiring. Repair as

 

 

 

 

 

necessary.

 

 

 

 

 

No Output on

Signal input switch not

Check signal input switch

 

Rear Channels

configured properly.

and reconfigure for 2-chan-

 

 

 

 

nel input.

 

Only

 

 

 

 

 

 

 

 

 

(using 2 inputs)

XCard is missing or not

Check XCard position and

 

 

 

 

placed

properly

in

repair or replace as neces-

 

 

crossover slot.

 

sary.

 

 

 

 

 

Rear Channels

Signal input switch not

Check signal input switch

 

are Non-Fading

configured properly.

and reconfigure for 4-chan-

 

 

 

 

nel input.

 

(using 4 inputs)

 

 

 

 

 

 

 

 

 

 

 

 

 

Amplifier Noise

Voltage spike from out-

Disconnect input signal to

 

(Turn-on Pop)

put of preceding com-

amplifier and turn ampli-

 

ponent is entering am-

fier on and off. If noise is

 

 

 

 

plifier through input sig-

eliminated, connect REM

 

 

nal.

 

 

lead of amplifier to source

 

 

 

 

 

unit with a delay turn-on

 

 

 

 

 

module.

 

 

 

 

 

 

Voltage spike from re-

Use a different 12 volt

 

 

mote turn-on lead is

source for REM lead of am-

 

 

entering

through REM

plifier. (i.e., battery direct)

 

 

input terminal.

 

If noise is eliminated, use a

 

 

 

 

 

relay to isolate amplifier

 

 

 

 

 

from noisy turn-on output.

 

 

 

 

 

 

 

– 32 –

Page 36
Image 36
Rockford Fosgate 400x4 operation manual Speaker Output, Low or Distorted, No Output on, Rear Channels, Only, Are Non-Fading