P 4040 (serv.man3) - JBL Car Audio User Guide / Operation Manual. Page 7

7

No audio

Low/no remote on voltage

Check connections; test turn-on voltage

Speakers are not connected or are blown

Check wiring; use VOM/DVM to measure speaker coil 
resistance

Distorted audio

Input sensitivity is not set properly

See Setting Input Sensitivity on page 5

Audio lacks “punch”

Speakers are wired with wrong polarity

Check polarity of connections; refer to Applications

Audio cycles off and on;

A protection circuit is turning the 

Verify the following: voltage of electrical system is

amber protection LED 

amplifier off and on

between 5 ~ 18Vdc; temperature is not 

(JBL badge on top panel)

over 194°F (90°C); no short circuits; speaker 

is flashing

loads are not less than 2 ohms (4 ohms in mono)

Audio cycles off and on;

GAIN is set too high

Set Input Sensitivity

amber protection LED

correctly (see page 5)

(on top panel) is flashing

Fuse blows

Incorrect wiring or short circuit

Check connections; refer to Applications

Many different system configurations are
possible using the crossovers and pre-amp
outputs featured in Power Series amplifiers.
If you are considering expanding you system
beyond what is shown here, please consult
your local JBL installation specialist who is
experienced in designing complex mobile
audio systems. 

Use the following guide to identify
symptoms and solve problems. Make sure
the vehicles electrical system is working
properly and power is reaching the JBL 
P-4020 P-4040.

Declaration of Conformity

Kongevejen 194B 
DK-3460 Birkerød
DENMARK

declare in own responsibility, that the products  

  described

in this owner’s manual are in compliance with technical

 

standard:

EN 55 013/8.1994

Steen Michaelsen

Birkerød. DENMARK. 8/98

EN 55 020/12. 1994

EN 55 013/A12/8. 1994

EN 55 020/12.1994

Birkerød, DENMARK. 10/98