nav system Nav system blank on 2007 ES350 vvt tube leaking oil

[Andrew Leonard]

I have a 2007 ES350 with the Mark Levinson combo gps nav, audio components, and climate controls on the one screen. The entire system goes blank intermittantly, and the screen reads not attached to outside antenna or some such folderoll. Lexus dealer wants to replace screen and all for 2000 dollars. Anybody have any suggestions as to a real fix rather than a replacement? I have also replaced the VVT oil feed tube at the back of the engine 2x already, it is leaking slowly again, head gasket has already been replaced, and adding a Lucas oil sealant only holds for 2 years. Anybody have this problem? Thanks, Hank