Alesis RA500 User Manual - Page 29

Chapter 4: Troubleshooting CHAPTER 4 TROUBLESHOOTING TROUBLESHOOTING INDEX Once all gain adjustments are made and proper operation is confirmed, no special considerations are required for Alesis Reference Series amplifiers. Aside from the front panel gain controls, there are no user adjustments or routine maintenance operations necessary (or available). If you experience problems while operating your RA150/300/500, please use the following table to locate possible causes and solutions before contacting Alesis Product Support for assistance. Symptom No audio from outputs Low output power Bass disappears, speakers sound out of phase Buzz from outputs Cause No input audio Bad cables Amplifier is turned down Is the amplifier very hot? Is the ambient temperature and/or the air flow in the rack high? If so, the amplifier may be in thermal protect mode (PROTECT LEDs on) Power is not connected Line voltage set improperly Amplifier accidentally set to "Bridge Mono" mode when wired for stereo Input cables are crossing a power cable or near a transformer Bad cables Problem with the source Noise induced from a bad AC ground or noisy AC circuit Solution Hook up inputs Replace the cables. Set levels to "12:00" or above Normal operation will resume when its internal temperature has dropped to reliable levels. Time for a coffee break. Set the switch on the back panel to the "120 V" position Set the switch on the back panel to the "stereo" position Make sure that the RA150/300/500 and its audio cables are kept away from power cables, other power transformers and wall warts. Use balanced inputs instead of unbalanced Replace the cable with a new, high-quality cable. Try plugging a known line-level source to the amplifier inputs to see if the problem remains. Connect to a different electrical circuit; use balanced inputs or plug amp and source into the same AC circuit RA150/300/500 Reference Manual 27