Jensen 880, 900, 400 Troubleshooting, Problem, Possible Cause, Corrective Action, POWER Amplifiers

POWER Amplifiers

Troubleshooting

Problem	Possible Cause	Corrective Action
Amplifier does not	No power to +12V	Check fuse(s)
turn on	terminal
	No power to REM	Check head unit fuse(s) and
	terminal	wiring
	Blown main fuse at	Replace fuse and identify
	battery	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	Input level control	Re-adjust the input level
sensitive	adjusted too high	(refer to page 8)
Distorted sound	Input level control	Re-adjust the input level
	adjusted too high	(refer to page 8)
Blows fuse(s) at amp	Power wires connected	Reconnect power wires
	backwards	properly
	Internal problem with	Take unit for service
	amp
Engine noise /	Ground loop(s)	Use good quality shielded
Alternator whine		RCA cables
	Faulty ground at amp	Re-ground amp to clean
		bare metal chassis
	Faulty ground at head	Re-ground head unit to
	unit	clean bare metal chassis
	Inductive coupling	Re-route RCA and/or
		speaker wires away from
		factory harnesses
	Input level on amp set	Re-adjust input level (refer
	too high	to page 8)
Thermal protection	Amplifier driving 2 ohm	If the amplifier “thermals”
activated	load for long durations	frequently while driving
		subwoofers, install fan to
		keep amp cool.

Short circuit	Blown speakers	Check all speakers
protection activated
	Speaker wire(s) shorting	Check for faulty wiring
	to ground
	Defective crossover	Faulty passive crossover
Low impedance	Amp connected to	Check speaker connections
protection activated	improper load
	Amp will not drive a 1	Verify that speakers are
	ohm mono load, 2 ohm	connected properly
	minimum in mono
	configuration
	Speakers defective/	Check speakers
	blown
	Faulty passive	Check crossovers
	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.

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.

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