Mackie HD1521 Owner's Manual - Page 10

HD1521 Appendix A: Service Information the mixer and the loudspeakers. You may have your positive and negative connections reversed at one end of one cable, causing one loudspeaker to be out-of-phase. If you think your Mackie product has a problem, please check out the following troubleshooting tips and do your best to confirm the problem. Visit the Support section of our website (www.mackie.com/support) where you will find lots of useful information such as FAQs and other documentation. You may find the answer to the problem without having to send your Mackie product away. Troubleshooting No power • Is it plugged in? Make sure the AC outlet is live (check with a tester or lamp). • Our next favorite question: Is the power switch on? If not, try turning it on. • Is the power LED on the rear panel glowing green? If not, make sure the AC outlet is live. If so, refer to "No sound" below. Poor sound • Is it loud and distorted? Make sure that you're not overdriving a stage in the signal chain. Verify that all level controls are set properly. • Is the input connector plugged completely into the jack? Be sure all connections are secure. Noise • Make sure all connections to the active loudspeakers are good and sound. • Make sure none of the signal cables are routed near AC cables, power transformers, or other EMI-inducing devices. • Is there a light dimmer or other SCR-based device on the same AC circuit as the HD1521? Use an AC line filter or plug the HD1521 into a different AC circuit. Hum • The internal AC line fuse may be blown. This is not a user serviceable part. If you suspect the AC line fuse is blown, please see the "Repair" section next. No sound • Is the input level control for the input source turned all the way down? Verify that all the volume controls in the system are properly adjusted. • Is the signal source working? Make sure the connecting cables are in good repair and securely connected at both ends. Make sure the output volume (gain) control on the mixing console is turned up sufficiently to drive the inputs of the speaker. • Make sure the mixer does not have a Mute on or a Processor loop engaged. If you find something like this, make sure the volume/gain is turned down before disengaging the offending switch. • Is the thermal indicator lit red on the rear panel? Make sure there is at least six inches of free space behind the HD1521. Poor bass performance • Check the polarity of the connections between 10 HD1521 • Try disconnecting the cable connected to the main input jack. If the noise disappears, it could be a "ground loop," rather than a problem with the HD1521. Try some of the following troubleshooting ideas: • Use balanced connections throughout your system for the best noise rejection. • Whenever possible, plug all the audio equipment's linecords into outlets which share a common ground. The distance between the outlets and the common ground should be as short as possible. Repair For warranty service, refer to the warranty information on page 15. Non-warranty service for Mackie products is available at a factory-authorized service center. To locate the nearest service center, visit www.mackie.com, click "Support" and select "Locate a Service Center." Service for Mackie products living outside the United States can be obtained through local dealers or distributors. If you do not have access to our website, you may call the Tech Support department at 1-800-898-3211, Monday-Friday, during normal business hours, Pacific Time, to explain the problem. Tech Support will tell you where the nearest factory-authorized service center is located in your area.