I have a 2000 G500 with the standard Audio 30 head unit. The middle part of the display suddenly disappeared. Therefore, I cannot see the radio frequency information, the lines for the volume display, etc. The balance of the display at the top and bottom works just fine. The information I am missing from the head unit display is generally repeated on the dashboard display (which continues to work just fine). Does anybody know the cause, if there is a fix, can the display (which is the fold-down door for the cassette) can be changed without changing the entire head unit, or if the only way to solve it is to change the head unit? Thanks in advance for any input.