Mackie M1400/M1400i Owner's Manual - Page 26

APPENDIX A: Service Info If you think your amplifier has a problem, please do everything you can to confirm it before calling for service, including reading through the following Troubleshooting section. Doing so might save you from the deprivation of your Mackie amplifier and the associated suffering. Of all Mackie products returned for service (which is hardly any at all), roughly 50% are coded "CND" - Could Not Duplicate, which usually means the problem lay somewhere else in the system. These may sound obvious to you, but here are some things you can check: TROUBLESHOOTING No power! • Our favorite question: 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 green light next to the power switch illuminated? If not, make sure the AC outlet is live. If so, refer to "No Sound" below. • The AC line fuse inside the cabinet is blown. This is not a user-serviceable part. Refer to "Repair" on the next page to find out how to proceed. No sound! • Are the GAIN controls turned all the way down? Slowly turn them up and see if you hear anything. • Is the signal source turned up? Make sure the signal level from the mixing console (or whatever device immediately precedes the amplifier) is high enough to produce sound in the amplifier. The SIG LEDs should be blinking to indicate that signal is present. • If the speakers are wired for BRIDGE mode, make sure the AMP MODE switch is set to BRIDGE . • If the OUTPUT APPLICATION switch is set to SUBWOOFER , make sure the LOW CUT FILTER frequency control is set to OFF or nearly OFF. If it is turned up above the subwoofer cutoff frequency, the output from the amplifier will be diminished. • Is the SHORT LED lit? Turn the POWER off, check the speaker connections and make sure that there are no strands of wire shorting across the speaker terminals. • Is the HOT TEMP STATUS LED lit? Make sure there is cool air available at the front of the amplifier. Make sure there is room at the sides of the amplifier for warm air to exit. Allow the amplifier to cool off. • Are there fuses in the speaker or in-line fuses in the speaker wire? Check 'em to see if they're blown. • Make sure the speakers are working properly. One side is way louder than the other! • Do the M•1400/M•1400i's meters read the same on both sides? If not, your source signal may be delivering an outof-balance stereo signal. • Are both GAIN knobs set to the same position? • Are the speaker(s) impedances matched? • Try swapping sides: Turn off the amp, swap the speaker cables at the amp, turn the amp back on. If the same side is still louder, the problem is with your speakers or speaker cabling. If the other side is louder now, the problem is with the mixer, the amp, or the line-level cabling. The stereo music sounds kind of sideways, and the bass frequencies diminish when standing center, but get louder as you approach one side! • Check the polarity of the speaker cable connections. You may have your positive and negative connections reversed at one end of one speaker cable. As soon as the music gets loud, the amp shuts down! • Check the M•1400/M•1400i's meters . Be sure that OL is not lighting up frequently or continuously. • Can the amp breathe? The M•1400/M•1400i amp draws its ventilation air in from the front and out through the side panels. It needs plenty of fresh air to stay cool. Do not block the ventilation ports. 26