JL Audio 300/2 owner manual Appendix C Trouble Shooting MY Amplifier DOESN’T Turn on, 8Ω bridged

APPENDIX C: TROUBLE SHOOTING

“MY AMPLIFIER DOESN’T TURN ON”

Check to make sure there is +12V at the “Remote” connection of the amplifier. In some cases, the turn-on lead from the source unit is insufficient to turn on multiple devices and the use of a relay is required. To test for this problem, jump the “+12V” wire to the “Remote” terminal to see if the amplifier turns on. If this does not work, proceed to the next step.

Check the fuse, not just visually, but with a continuity meter. It is possible for a fuse to have poor internal connections that cannot be found by visual inspection. It is best to take the fuse out of the holder for testing. If no problem is found with the fuse, inspect the fuse-holder.

“I GET A DISTORTED / ATTENUATED SOUND COMING OUT OF THE SPEAKER(S)”

Check the speaker wires for a possible short, either between the positive and negative or between a speaker lead and the vehicle’s chassis ground. If a short is present you will experience distorted and/or attenuated output.The “Low Ω” light may also illuminate in this situation. It may be helpful to disconnect the speaker wires from the amplifier and use a different set of wires connected to a test speaker.

Check the nominal load impedance to verify that each channel of the amplifier is driving a load between 1.5 - 4Ω

(3 - 8Ω bridged).

Check the input signal and input signal cables to make sure signal is present at the “Amplifier Input Section” and the cables are not pinched or loose. It may be helpful to try a different set of cables and/or a different signal source to be sure.

“MY AMPLIFIER SHUTS OFF ONCE IN A WHILE, USUALLY AT HIGHER VOLUMES”

Check your voltage source and grounding point.The R.I.P.S. power supply is rated to operate with source voltages between

11 - 14.5V. Shutdown problems at higher levels can occur when the charging system voltage drops below 10 volts.These dips can be of very short duration making them extremely difficult to detect with a common DC voltmeter.To ensure proper voltage, inspect all wiring and termination points. It is also a good idea to improve the vehicle’s factory ground wire and termination point. Grounding problems are the leading cause of mis-diagnosed amplifier failures.

“MY AMPLIFIER TURNS ON, BUT THERE IS NO OUTPUT”

Check the input signal using an AC voltmeter to measure the voltage from the source unit while an appropriate test tone is played through the source unit (disconnect the RCA cables from the amplifier prior to this test).The frequency used should be in the range that is to amplified by the amplifier (example: 50 Hz for a sub bass application or

1 kHz for a full range / high-pass application). A steady voltage should be present at the output of the RCA cables. If you are receiving a sufficient voltage (between 0.2 and 8.0- volts), check to ensure that the speaker wires are making a good connection with the metal inside the amplifier. The connectors are designed to accept up to an 8 AWG wire. If you are using significantly smaller wire (14 AWG or smaller), you may have difficulty making an adequate connection. In this case, you may find it necessary to “fold” the wire over once (or twice!) so as to make a solid connection. Make sure to strip the wire to allow for a sufficient connection with the input or output of the amplifier.

Check the output of the amplifier. Using the procedure explained in the previous check item (after plugging the RCA cables back into the amplifier) test for output at the speaker outputs of the amplifier. Unless you enjoy test tones at high levels, it is a good idea to remove the speaker wires from the amplifier while doing this. Turn the volume up approximately half way.

5 volts or more should be measured at the speaker outputs. This output level can vary greatly between amplifiers but it should not be in the millivolt range with the source unit at half volume. If you are reading sufficient voltage, check your speaker connections as explained above.

“MY AMPLIFIER’S OUTPUT FLUCTUATES WHEN I TAP ON IT OR HIT A BUMP”

Check the connections to the amplifier. Make sure that the insulation for all wires has been stripped back far enough to allow a good contact area inside the amplifier terminal.

Check the RCA connectors to ensure that both the center pin and the outer shield are making good contact with the input jacks on the amplifier.

“HOW DO I PROPERLY SET THE INPUT SENSITIVITY ON MY AMPLIFIER”

Please refer to Appendix B (page 13) to set the input sensitivity for maximum, low-distortion output.

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