Phone display illuminating when phone not in use

[brownd1950]

Most nights between 2300hrs and midnight but usually between 2300hrs and 2320hrs the display on my phone (BT6610) illuminates as if a call was about to be received and a message on the display states “line cord error “. The message appears for approximately 10 secs and then disappears and the phone will go back to normal again approx 10 secs after that.
This is most annoying at that time of night particularly if you are in bed and suddenly you think you are about to receive a call. Would I be correct in thinking that this is BT doing work or checks at the exchange especially as it occurs always at that time of night.

Any help or suggestions would be most welcome.

[rbz5416]

I have a set of 8500s & one of them does this, but randomly rather than at a set time. I just ignore it as I'm 99% sure it's completely spurious as the broadband never drops at the same time. I've also never seen it on any of the other handsets, including the one on the bedside cabinet.

Does your broadband log show a disconnection at this time? Do you have multiple handsets & if so, does it happen on all?

I'd try plugging directly into the test socket for a couple of days to see if it goes away. If not, I'd suspect mains interference from a device/appliance, maybe on a timer.

[Les-Gibson · Accepted solution]

If your phoneline is still on copper then it's almost certainly automated diagnostics being conducted in your exchange 

[brownd1950]

Hi, thanks for your reply. 
I have 4 handsets and the problem affects them all. Obviously, the one that I have on the bedside cabinet is the most annoying as it partially lights up the bedroom when this takes place just as you are nodding off to sleep. I’m sure this is BT doing checks and nothing to be concerned about. 

[brownd1950]

Thanks for your reply. Your response confirms what I had suspected.