Radio (concert single din) won’t turn on after Sade mode

[Benhey90]

Hi all this is my first post after getting myself an Audi A3 sportback 2007. All has been fine for past month. Then this morning I came to turn the car on. And the radio popped itself into SAFE mode, entered the code which I know is correct as I installed a Handsfree Bluetooth (connects2) device few weeks ago. But the radio then just turned itself off immediately after acknowledging the code. I.e displays the radio station for a split second then go off. When I try turn it back on I’m back to the start again (SAFE mode). I thought maybe a loose wire somewhere, so removed the radio, unplugged all wires and checked, then, plugged back in. But same problem persists. The fact it’s been working fine for a few weeks since installed the Handsfree makes me think it wasn’t the fact I installed this incorrectly? But I’m not sure to be honest. Anyone with any advice or has experienced similar, would be great to here from you. Many thanks