Jensen POWERPLUS 420 - Manual (Page 13)

PowerPlus Amplifiers
13
Troubleshooting
NOTE: If the protection light is activated with no speakers connected to
the amplifier, and all the power connections are correct, this would
indicate an internal problem with the amplifier.
Problem Possible Cause Corrective Action
Amplifier does not
turn on No power to +12V
terminal Check fuse(s)
No power to REM
terminal Check head unit fuse(s) and
wiring
Blown main fuse at
battery Replace fuse and identify
cause of failure
Blown fuse at amplifier Replace fuse and identify
cause of failure
Faulty ground Re-ground main power
ground to bare metal
chassis
Volume control too
sensitive Input level control
adjusted too high Re-adjust the input level
(refer to page 8)
Distorted sound Input level control
adjusted too high Re-adjust the input level
(refer to page 8)
Blows fuse(s) at amp Power wires connected
backwards
Reconnect power wires
properly
Internal problem with
amp Take unit for service
Engine noise /
Alternator whine Ground loop(s) Use good quality shielded
RCA cables
Faulty ground at amp Re-ground amp to clean
bare metal chassis
Faulty ground at head
unit Re-ground head unit to
clean bare metal chassis
Inductive coupling Re-route RCA and/or
speaker wires away from
factory harnesses
Input level on amp set
too high Re-adjust input level (refer
to page 8)
Thermal protection
activated Amplifier driving 2 ohm
load for long durations If the amplifier “thermals”
frequently while driving
subwoofers, install fan to
keep amp cool.
Short circuit
protection activated Blown speakers Check all speakers
Speaker wire(s) shorting
to ground Check for faulty wiring
Defective crossover Faulty passive crossover
Low impedance
protection activated Amp connected to
improper load Check speaker connections
Amp will not drive a 1
ohm mono load, 2 ohm
minimum in mono
configuration Verify that speakers are
connected properly
Speakers defective/
blown Check speakers
Faulty passive
crossovers Check crossovers
Poor bass response Speakers out of phase Check speaker polarity;
reverse the connection to
one speaker only if two
subwoofers are connected
to the amplifier.