NEC DT300 series phone answers automatically

[JordanT91]

Hi all. I've got a bit of a weird issue with an NEC DT300 series phone. When you call that particular extension, the phone beeps once and automatically answers the call. This is causing a problem because the phone is located in the staff room and nobody knows the phone is ringing. I've checked the ring tone is correct and I've trawled the online manuals for this model but there's nothing that mentions automatic answering. There's an intercom feature but as far as I can tell that isn't the issue. There's also the handsfree feature but that still requires pressing the speaker button when the phone is ringing.

 

Has anyone come across this before? It's only been happening for a couple of days and I haven't changed anything on the NEC SV8300 server for months so I assume someone has pressed the wrong button with fat fingers.

 

Thanks in advance.