I have a Mark Levinson sound system with navigation, My screen won’t work. Will the screen on a newer model fit like 4th generation LS fit 3rd generation? How do you know if it’s the screen that’s bad or the Amplifier from Mark Levinson that’s bad?
Many thanks In advance …

1. Check fuses (https://fuse-box.info/lexus/lexus-ls...uses-and-relay)
2. Screens are not backward compatible from the 4th gen or even between 01-03 and 04-06 afaik
3. Typically a bad amp will only affect audio and not the screen unless water has gotten into your trunk somehow and affected both modules?
4. Does your radio work? How about climate control?
5. It could just be the digitizer which has rarely been known to go out (https://www.ebay.com/itm/392939534540)

My radio, CD player and navigation and cassette doesn’t work.
The only thing that does work is climate controls, rear defroster, park assist.