Sunfire IV manual Your amplifiers shut down often

APPENDIX

Your amplifiers shut down often

Check the following:

•Make sure each speaker's average impedance is not less than your amplifi ers can safely handle.

•The amplifi ers have good ventila- tion, no vents are covered.

•Try setting all the speakers to Small, and let your subwoofers handle the heavy bass.

•Check that the amplifi er power output is a good match for your speakers. If your speakers are ineffi cient, consider using larger power amplifi ers.

Reset procedure

The TGIV is a microprocessor controlled device of great complexity. Occasional power fl uctuations and spikes may cause the TGIV to "lock up" or act strangely. The TGIV can be reset as follows.

Warning: the TGIV will be reset to the factory defaults, and will clear all memory. All your

stored OSD settings and Tuner presets will be erased.

•On page 57, write down your calibration settings, input settings, Tuner presets, and any other set- tings you have made.

•Press the power button to turn the unit off, or turn it off from the wall for a moment.

•Press and continue to hold down the front panel Power button and the Tone DOWN button at the same time.

•The TGIV will power on and cycle through the display. Keep holding the buttons down until "Resetting to Factory Defaults" appears in the front panel display

•When the TGIV has been reset, it will shut off.

•Turn the TGIV back on and it will go to the default screen. It has now been reset.

•If the TGIV has to be reset regu- larly, you should invest in a good quality AC line conditioner.

Updating firmware problems

•See page 51

•If you have a Palm Pilot™ or simi- lar device with “HotSync™” or its equivalent, you may need to dis- able this software before proceed- ing. This software ‘seizes’ control of a serial port on your machine and prevents the Sunfi re software from accessing that port. Use an- other port or disable HotSync.

•Check that the serial cable is con- nected correctly between the TGIV and your computer's serial port.

A Hum is heard in your speakers

This problem is more than likely caused by a “ground loop” in your sys- tem, rather than a fault in the TGIV. Follow these steps to isolate the main cause of the hum, there may even be more than one.

•Remember to turn off all compo- nents in your system, including the TGIV, before disconnecting or connecting any cables.

•Disconnect the following items in order, and check each time if the hum has gone away:

•Disconnect all cables which come from outside the room, such as cable TV, satellite TV, or roof top antennas. Make sure that they are disconnected where they fi rst enter the room, so they are making no connection to the TGIV or the TV, or any other component. If the hum is caused by the cable TV line, then you will need a “ground loop isolator.” This is an inexpensive device fi tted in line with the coaxial cable feed. Contact your cable company or your Sunfi re Dealer for assistance.

•Disconnect all connections from the TGIV to your TV.

•Disconnect any component which has a grounded power cord.

•If the hum persists, disconnect all the source components one at a time from the back of the TGIV, until you identify the problem.

•Ground loop isolators are available for audio lines and video. Ask your Sunfi re Dealer for assistance.

•Try moving the speaker cables away from any power cords. Try just one speaker, connecting it to different channels and see if an amplifi er channel is bad.

•If you are still having a problem, remember that Sunfi re’s dealers and technical support staff will as- sist you.

Other causes of noise

•Speaker noise may also be caused by interference or noise on your AC line. Make sure there are no large appliances sharing the line, or halogen lamps or light-dimming Triac devices.

•Try connecting your system to an- other AC socket on a separate line.

•If the hum is heard from within the TGIV and not through the speak- ers, this may also be caused by interference on the AC or DC lines. The power transformers may turn this interference into an audible noise. Internal hum can be made worse by a shelf or cabinet reso- nating, so try moving the TGIV to another shelf.

•Try moving your components further away from the TV, especially if you ever notice the screen has changed color in the area closest to the component.

•If you have very high effi ciency speakers, these may show up noise which other speakers may not.

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User's Manual