We have DMC-10RS intercom system in our house. All them squeal when the power source is on. I had to unplug the hub to make them quiet. I cked the power supply and its putting out 12.2V,ok. Any ideas what is causing this?

Check power supply for proper voltage of 12 volts DC.
-If there are multiple Hubs, check voltage on all Hubs
If the voltage is not 12V, try replacing the power supply
226888 Power Supply
-If the voltage is ok, disconnect 1 room station at a time. If there a multiple Hubs, disconnect the last Hub. As each room station and/or door station is removed, have someone else listen to see if the squeal goes away. There is a chance that one bad room or door station is causing the issue.
oIf the squealing stops, add in the previous stations that had been disconnected. If all stations other than that room station are ok, do not hook up that station. There are no replacement stations available for this system. If the squealing continues with any of the stations hooked up, there is a bad HUB. DMC-10 Hubs are NLA and cannot be repaired. The best option for a replacement is the I2000 Kit
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