US Blaster USB 3451 Manuel D'instructions page 6

USB 3451 / 3461 / 3471 / 3481
Car Power Amplifier
TROUBLESHOOTING
Before removing your amplifier, refer to the list below and follow the
suggested procedures. Always test the speakers and their wires first.
AMPLIFIER WILL NOT POWER UP.
Check for good ground connection.
Check that remote DC terminal has at least 7V DC.
Check that there is battery power on the + terminal.
Check all FUSES.
Check that Protection LED is not lit. If it is lit, shut off amplifier briefly and then repower it.
HIGH HISS OR ENGINE NOISE(ALTERNATOR WHINE) IN SPEAKERS.
Disconnect all RCA inputs to the amplifier, if hiss/ noise disappears , then plug in the component
driving the amplifier and unplug its inputs. If hiss/noise disappears, go on until the faulty/noisy
component is found. It is best to set the amplifier input level as insensitive as possible. The best
subjective S/N ratio is obtainable this way. Try to drive as high a signal level from the head unit as
possible.
CAR POWER AMPLIFIER PROTECTION LED COMES ON WHEN THE AMPLIFIER IS
POWERED UP.
Check for shorts on speaker leads.
Check that volume control on the head unit is turned down low.
Remove speaker leads ,and reset the amplifier. If the Protection LED still comes on, then the
amplifier is faulty.
The amplifier will shut down automatically when the units temperature got up to 80ºC
This will protect the unit damage.
AMPLIFIER(S) GETS VERY HOT.
Check that the minimum speaker impedance for that model is correct.
Check for speaker shorts.
Check that there is good airflow around the amplifier. In some applications, an external cooling fan
may be required.
DISTORTED SOUND.
Check that the Level control(s) is set to match the signal level of the head unit.
Check that all crossover frequencies have been properly set .
Check for shorts on the speaker leads.
HIGH SQUEAL NOISE FROM SPEAKERS.
This is always caused by a poorly grounded RCA patch cord.
WARNING!
1. Over high volume will damage your speakers.
2. Be cautious when you use the amplifier near gasoline tank and electric wires.
3. Protect the connecting wires and parts to avoid any damage or short circuit.
4. The power must belee from the anode of the battery via FUSE.
5. The sound system must be in turning-off situation when you check the amplifier.
6. Be sure that you use the same type of FUSE when you need to replace it .
* We reserve the right to make needed change or improvement to the product, without informing
the customer about this in advance.
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