No sound from infotainment system.

[zippdee]

Hi. I have a qashqai j11 2016 n connecta. A couple of days ago I turned on the radio and no sound.

I have tried a reset but no joy. I rang nissan dealer they wanted £150 to diagnose.  And if I need a new headunit it's £3000 thats three thousand not a typo lol. 

Has any got any ideas. A friend suggested a memory fuse gone in the unit but I can't find one listed.

Any ideas welcome.