One of my best friend have a 01 GS 430 with ML/Nav. The dealer he purchased from had installed a DVD headrest system. Now 6 months later when he turns on no sound comes out of the speakers and then about 5-10 minutes it comes on at it highest setting. He took it to the dealer and they said it's not covered because of the aftermarket work done by the original dealer. (Non Lexus Dealer). But they think that 1. Head Unit or 2. Amp. Based on the information I found here I think it maybe a amp problem which we have source that we can pick one up for about 400.00 new. Other symptoms are the audio screens are greyed out so you can't adjust the balance and fade and the Tone control have the Bass and Treble but the Mid sliders are missing from the screen. We want to get the amp and replace but if it's something else like Nav Head unit well we are talking 2,000.00. Anyone have any suggestions or course of action it will be much appreciated. Original dealer is no help.

 

Have you tried the amp in another system? Also, is there any output from the HU at all? (pre amp outs) Try hooking up a set of speakers or headphones to the preamp out. if you get a signal, then you know that the amp is going bad. If you don't get a signal then it's the HU going wacky.

Percy