Try this----
From an old FAQ sheet:
Question: I have a flashing HOLD light on my phone, how do I clear it?
Resolution:
1) Press the Intercom button, then press the Hold button.
2) This will cause a phone on the system to ring. Use this ringing phone as a marker of the
phone you will need to go to. You do not need to answer that phone, however you will need
to go to that phone and perform the following while it is in an idle state.
3) Press the Intercom button and dial #3 followed by the extension number of the phone with
the flashing Hold light.
