Graphite 2100 - beeping like morse code

[mspring501]

An obscure one. I have a twin set of BT Graphite 2100s.  The add-on base unit (not the handset) has started to beep roughly 3-4 times every 2 seconds continuously (in a dot, dot, dot, dash fashion - rather like morse code).  So far, I've turned it on and off, switched the handset batteries with the other handset and reset the handset. I've also swapped the handsets over.  There is no troubleshooting guide that I can find that describes this continuous beeping.  Any thoughts? 

I know it's an old model but it's never had an issue and so no need to replace it before.

Thanks.

[Keith_Beddoe]

@mspring501 

Welcome to this user forum for BT Retail phone and broadband customers.

Have you tried powering down the main base unit for a couple of minutes, just in case there is a DECT communication issue?