Updating ﬁrmware problems

APPENDIX

•See page 52

•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 Sun re software from accessing that port. Use an- other port or disable HotSync.

•Check that the serial cable is connected correctly between the TGR-401 and your computer's se- rial port.

A Hum is heard in your speakers

This problem is more than likely caused by a “ground loop” in your system, rather than a fault in the TGR-

401.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 TGR-401, 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 rst enter the room, so they are making no connection to the TGR-401 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 inexpen- sive device tted in line with the coaxial cable feed. Contact your cable company or your Sunre Dealer for assistance.

•Disconnect all connections from the TGR-401 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 TGR- 401, until you identify the problem.

•Ground loop isolators are available for audio lines and video. Ask your Sun 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 ampli er channel is bad.

•If you are still having a problem, Sun re’s dealers and technical support staff will assist 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 TGR-401 and not through the speakers, 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 resonating, so try moving the TGR- 401 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.

General notes

Check the following to get the best out of your TGR-401:

•Each speaker's average imped- ance is not less than 4 ohms.

•The TGR-401 has good ventilation, and none of its vents are covered.

•Try setting all the speakers to 90 Hz, and let your subwoofer handle the heavy bass.

•Check that the ampli er power output is a good match for your speakers. If your speakers are inef cient, consider using an exter- nal power ampli er.

User's Manual