Afternoon all,

Rained last night (lol that's another post) only a bit of water on drivers rubber mat.

Fired up the radio, no sound, no sound on anything.

Could cycle through the TV, CD on screen (the headunit seemed to function fine) etc, and when turned up the volume could hear a hiss, but no actual audio.

Checked in the back, no water in the boot, nice and dry. Though I did find a clear piece of plastic that looked like it had a butyl rubber seal from the factory to fix to the passenger side and perhaps shelter any water coming in over it.

Is there any water in the left hand side of the boot behind the cover you can remove? This is where all of the comms and ICE stuff lives. Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

Dry as a bone

I'd start by checking the various fuses in the front passenger and rear fuse boxes in case water ingress caused a short somewhere.

I'd also disconnect the battery for 2 minutes (solves a lot of problems on the L322).

If this yields no results, there may be some coincidence and there could be a fault on the MOST fibre optic system somewhere. This isn't as scary as it sounds - just a case of plugging a fibre optic loop to bypass each unit until you find the culprit. Each infotainment item is daisychained, so if one fails, the whole system breaks. It ends with the audio amplifier.

Also, if not already aware, I see you're Hampshire based. We (the Hampshire contingent) meet up monthly. Check the 'Events' section on the forum - next meet is pencilled for 21st September. 2015 Range Rover Autobiography 4.4 SDV8

Thanks Gary for the comprehensive response. Be great to meet some fellow owners too, so I would be up to attend if that was ok.

if it was the MOST bus it would usually have blank screen with the orange power light on the head unit.

Its most likely to be the amp in the rear left quarter.

Ive become Most (sorry for the pun) with the infotainment system in the L322 over the last week chasing my own black screen issue.