Coustic & 480QE, 320QE owner manual Ro U B L E S H O Ot I N G S E C T I O N, Symptom Probable Cause

www.coustic.com

	T RO U B L E - S H O OT I N G S E C T I O N
SYMPTOM	PROBABLE CAUSE
1 No power	Check connections to the amplifier's Ground, B+ & Remote
	terminals. Check connection at "+" terminal of the battery.
	Check the remote turn-on terminal. Ensure it receives power
	when the source is turned on (or when the switch is turned
	on). Refer to the Installation Section. Check the power line
	fuse: if fuse is blown, replace it; if fuse continues to blow,
	check the power wire and also the amplifier for a short. If the
	short is in the power wire, fix it; if the short is in the amplifier
	itself, see your Coustic dealer.
	Check the voltage at the amplifier, and the remote ON/OFF
	lead. The voltage should measure between 11 V-15V. If the
	measurement is beyond this range, have the source unit
	checked out by an authorized dealer.

SYMPTOM

8.Whining noise when engine is running with noise varying with the accelerator (noise level varies with source unit volume.control).

9.Constant level whining noise (most noise with source unit volume at minimum)

PROBABLE CAUSE

Reroute power cable from the battery to the source unit directly, bypassing the battery terminal in the fuse box. Check power connections to be sure they are clean.

Check ground connections to be sure the ground wire is in direct contact with the bare metal surface of chassis (with that spot scraped clean of any paint).

Check for a ground loop in the system. Turn the system off and one by one change the ground connections

(by changing to a different contact point, scraping the level constant irrespective of metal clean of any paint, rust or grease). Turn the system on and check for whining noise after each ground change.

2.	Power without sound with	Turn the amplifier off, and Check all input & output signal
	red power/protection	cables and connections. Check the speakers for a short with
	indicator on	a VOM or by connecting them to another audio system. After
		making sure everything is normal, turn the amplifier on again.
3.	Power without sound with	The continuous red light of the power indicator signals a high
	red power indicator on	internal operating temperature which results in the amplifier
		switching off temporarily; when the amplifier cools down to a
		safe level, the amp will automatically restart.
4.	No sound from one side	Check balance control.
		Check speaker connections.
		Check signal input connection.
5.	Very low sound from	Check your radio's fader control.
	both radio & tape	Check the amplifier's Input Sensitivity Level.
6.	Frequent automatic amplifier	This indicates that the amplifier is operating at a continually
	shut down	undesirable high internal temperature.
		High operating temperature caused by inadequate ventilation.
		(Refer to the sub-section titled LOCATION for a better amplifi-
		er location.)
		High operating temperature can be caused by an excessively
		low impedance load, say below 2 ohms. Check for bad
		speakers and/or electronic crossover, proper passive
		crossover components; if all else fails, try rewiring the entire
		system. A high operating temperature can be caused by an
		incorrect input sensitivity level (refer to sub-section titled
		INPUT SENSITIVITY ADJUSTMENTS for correct setting).
7.	"Motorboating": The amplifier	Check the amplifier's connection to the battery.
	power indicator going off	Check battery voltage. If low, recharge or replace battery.
	repeatedly when the audio	Check all ground connections.
	system is on.

CAUTION:

10.Radiated noise: crackling noise on FM which is not present when playing tape or CD (noise varying slightly with accelerator, but is present at all times)

Do not disconnect the Power Amplifier's ground when the system is on. This could damage the amplifier.

Check for defective signal cables. Disconnect signal cables at the amplifier and listen carefully for noise. If the noise dis- appears, run a test pair of signal cables. If there is no unde- sirable whining noise, reconnect to the amplifier with the new pair of signal cables. Check the battery ground connection to the vehicle chassis to make sure it is tight and clean.

Check the battery negative terminal connection to make sure it is tight and clean.

Check if the noise is actually radiated noise: Tune a portable radio to the same FM station. Move the portable radio close to the vehicle engine. If the crackling noise comes from the portable radio, then the noise you have in your vehicle audio system is radiated noise.

Check with a VOM to make sure the antenna is really ground- ed to the vehicle chassis.

To ensure a true ground, break the plastic covering of the antenna lead and solder a piece of heavy wire (minimum 14- gauge) to the braided shield.

Ground the other end of the wire at the same point as the radio ground.

Check spark plug wires. They should be suppression-type wire and less than 2 years old. Otherwise, replace them with good quality suppression cables.

Make sure the engine block is grounded to the vehicle chas- sis at a bare metal spot (scraped clean of paint, rust and grease).

Make sure hood is also grounded. If not, use a ground strap (which is available from any auto parts store) to ground the hood to the vehicle chassis.

16 17