After a loss of landline broadband signal last night (01:45 -02:20), which coincided with general BT broadband troubles spike @02:00 recorded on Down Detector, the broadband signal returned but the buzzing on my Decor 2600 handset returned.
As before this buzzing noise is there all the time when the handset is in use, even when performing a "Quiet Line " Test using 17070, and only goes away if I use the "Handsfree" facility.
Resetting the phone's values to default and re-booting it doesn't cure the problem.
Similarly, detaching the handset from the base unit doesn't cure it. . . . ditto performing a phone reset with the handset removed.
The only thing that seems to work is turning the Smart Hub off and then resetting the phone and then restarting the Smart Hub 2.
This seems to be a problem exclusive to the Decor 2600 handset because removing it and substituting a handset from a previous Decor model again cures the problem.
This phenomena has only been experienced within the last 3 months . . I wonder what has changed during this period ?
Anyone care to venture an opinion as to what the fluffing hell is going on ?
If replacing the handset cures the problem then it is obvious the handset IS the problem.
The problem only occurs when the Exchange turn off the broadband signal to do maintenance or supply a Firmware update to the Smart Hub 2. It was a firmware update that was coincident with the most recent problem.
There seems to be an odd interaction between the Smart Hub and this phone handset (A BT product).
I've noticed this problem and its resolution is inversely correlated with another problem I've got with Devolo powerline plugs.
When the phone line has no background hum, the Devolo unit providing the uplink reports low bandwidth (Downlink is normal). When the background hum is present on the phone, the Devolo unit reports normal bandwith for the uplink connection (Downlink normal).
So, I suspect that the Devolo unit is involved in this problem and that BT Exchange generated Smart Hub 2 reset triggers it.
The problem is only cured by me turning off the Smart Hub 2 locally and then resetting the phone from its on board software menu.
As only using "Handsfree" cures the problem then it is obvious the receiver IS the problem.