‘97 Disco 1….looking for 12v source for a bluetooth dongle, I temporarily disconnected the purple/black two pole connector to CD changer….system seems not to have liked that - radio is now unresponsive to all button pushes except trying to enter the five digit code starts beeping at me for a couple of minutes.
I’ve tried disconnecting negative battery terminal, code entry to no avail. Now am trying the 90min ignition key position 1 trick.
Any other ideas? Thanks.

 

key must be in pos II for ~90 mins for the radio to accept a code (not pos I). I am surprised to hear the purple/black connection to the CD player disrupted power to the head unit. That makes me suspect someone has been there before you.