Stereo 
will go to black screen on start up
If your screen goes black on 
start up the common cause of this is voltage leak from the reversing lights or 
possibly the software is being blocked.
Trouble shooting.
a) using a pin press the reset button on the top left corner - this will clear 
the software. If it initially works but reverts back to a stage when the issue 
continues then remove the earth off the battery overnight.
b) put the car in reverse.  If you get an image then you either have faulty 
wiring or a voltage leak.  This can also be tested by cutting the trigger 
wire.