Sherbourn Technologies owner manual Problems Updating PT-7010AFirmware, “Hum” Noises

display. Keep holding the buttons down until “Resetting to Factory Defaults” appears in the front panel display. When the PT-7010A has been reset, it will shut off. Turn the PT-7010A back on and it will go to the default screen. It has now been reset. If the PT-7010A has to be reset regularly you should invest in a good quality AC line conditioner or contact Sherbourn for technical support.

Problems Updating PT-7010A Firmware

•Check that the serial cable is connected correctly between the PT-7010A and your computer’s serial port.

If you have a Palm Pilot™ or similar device with “HotSync™” or its equivalent, you may need to disable this software before proceeding. This software ‘seizes’ control of a serial port on your machine and prevents the Sherbourn software from accessing that port. Use another port or disable HotSync.

For additional information regarding technical issues encountered with updating the firmware of the PT-7010A, visit the Sherbourn website at www.Sherbourn.com.

“Hum” Noises

This problem is more than likely caused by a “ground loop” in your system, rather than a fault in the PT-7010A. Follow these steps to isolate the main cause of the hum; there may even be more than one. Remember to turn off all components in your system, including the PT-7010A, 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 first enter the room, so they are making no connection to the PT-7010A 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 fitted in line with the coaxial cable feed. Contact your cable company or your Sherbourn Dealer for assistance.

•Disconnect all connections from the PT-7010A 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 PT- 7010A, until you identify the problem. (Ground loop isolators are available for audio lines and video. Ask your Sherbourn 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 amplifier channel is bad.

If you are still having a problem, remember that Sherbourn’s dealers and technical support staff will assist you.

Other Probable 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 another AC socket on a separate line.

•If the hum is heard from within the PT-7010A 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 PT-7010A 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 efficiency speakers, these may tend to reveal noises which other speakers do not.

55