Harman GTO-3EZ Troubleshooting, Bass Boost, Power/Protection LED, Problem, Causes and solutions

Bass Boost

The Bass Boost control provides up to 12dB of bass boost at 45Hz. Set this control according to your personal taste, but be careful not to set the control at a high enough level to cause audible distortion or bottoming of your subwoofer.

Power/Protection LED

Power/

Protection

LED

The GTO amplifier Power/Protection LED’s color indicates the amplifier’s operational status:

LED is orange: Normal operation (power is on)

LED is off: Amplifier is in standby mode

LED is red: Amplifier is in protect mode

If the amplifier is in the protect mode (the LED is red), see Troubleshooting, below.

Troubleshooting

If your amplifier isn’t performing the way you think it should, check to see if the problem is covered in this section before calling your dealer or contacting JBL customer service.

Problem	Causes and solutions
No sound (the amplifier’s	• Check that the amplifier’s +12V and GND connections have been properly
Power/ Protection LED is off):	made.
	• Check if the fuse on the +12V wire located near the battery is blown; if so,
	replace it with an identical fuse.
	• Check all amplifier fuses; if any are blown, replace them with identical fuses.
	• If you are using the amplifier’s REM connection for turn-on, check that the
	wire is properly connected to the audio system’s remote turn-on wire or to the
	vehicle’s ACC power terminal.
	• If you are using the amplifier’s Auto Turn-On circuit for turn-on, check that the
	amplifier’s Auto Turn-On switch (on the amplifier’s bottom panel) is set in the
	“On” position.
No sound (the amplifier’s	• Check that all amplifier input and speaker connections have been properly
Power/ Protection LED is	made.
orange):	• Check that the amplifier’s Gain controls are not turned all the way down.
	• Check that the vehicle audio system’s source unit’s volume control is not
	turned all the way down.
No sound (the amplifier’s	• Confirm that the vehicle’s electrical system is supplying between 9V and 16V
Power/ Protection LED is red):	DC to the amplifier. If the supply voltage is outside of this range, correct the
	condition before attempting to use the amplifier.
	• If the amplifier has overheated, wait until it has cooled down before attempting
	to use it again.
	• Disconnect all speakers from the amplifier and attempt to turn it on again:
	– If the amplifier turns on (the Power/Protect LED is orange), there is a short
	circuit in one or more of the speaker wires. Correct all short circuits before
	reconnecting the speakers to the amplifier.
	– If the amplifier does not turn on (the Power/Protect LED is still red), contact
	your authorized JBL dealer for assistance.

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