I have a 2001 LS430 with 200k miles. The radio and screen stopped working but you can get music through the CD player.

My Question: Does this mean that the Mark Levinson amp still functions? (I would think so). If so I will move forward with getting an aftermarket android head unit.

If you have no display at all on the Nav screen, then chances are it is that that has failed.
You can replace it with a used Nav screen or with one of the Android units.
The actual Nav unit is in the trunk as are the Amp and Radio Tuner.

Thank you. The screen is out (although i accidentally discovered that you can see some details when you wear polarized sunglasses) (crazy but true).

The radio and nav however do not function at all. As I can play CDs perfectly (I don’t see any info on the screen, but hear the music) am I correct then that the amp still functions?

I intend to modernize the car by installing an android based head unit which will provide full Bluetooth, a large touchscreen, radio, and car play. (And allow me to install a cheap backup camera).

please advise. thank you.

Not crazy, LCDs work by allowing light through or not, so polarisation occurs. If you can see the screen change with the polarised sunglasses and the touch functions still work, then it is the LCD backlight that has failed.
If you have sound then the CD player and Amp are working fine but you should also be able to select the radio and hear something.
I've not installed an Android head unit but others have and I'm sure will chip in.
Search for the Android threads on here and read up on those.

Thank you very much for your replies. The replacement head unit is relatively cheap and swapping it seems fairly easy. Knowing that the amplifier functions is the last hurdle. Im pulling the trigger on the head unit.

Once again, many thanks.