Red screen of death on Symphony II
 

I had the red screen of death on my Symphony II yesterday when I turned the key on. No response to any input, or when switching the car off (still glowing red, all buttons lit up). I had to pull the unit out and disconnect and re-connect the power plug. I had this before a year ago, but after disconnecting and plugging back in the unit always worked ok afterwards.
I also have a intermittent safe mode, which was away for a good few months, but now comes on every time the car sits for a couple of days without being driven.

I installed the unit myself and it is VCDS coded to Symphony II.

I can live with it but just wondering if there is a fix or if its due to something obvious I may have done wrong with the install?

I also have a speaker to earth error, not sure if that could be causing the problem.