Electrics: 54Plate XC90 Radio Dead

[Dieseltractor]

So the radio has stopped working on my XC90, and because the reversing sensors work through the radio they have also stopped working. Sometimes when you switch it on and fiddle with the buttons it says Premium Sound System on the display but it does nothing else, won't play or even eject CDs.
I have checked for 12v on the amp under the seat (which is dry by the way) and there is 12v there. My unconfirmed suspicion is that the amp is dead but I don't know what else to check and I think it needs coding if I replacement is needed.
Any ideas before I submit myself to the expense and mysery of taking it to a main dealer?

[Simon Jones]

Not sure that a faulty amp would prevent CDs from ejecting. Sounds like a problem with the head unit.

[oragex]

As above, the amp shouldn't be preventing from ejecting CD's. Plus, if there's no signs of corrosion on it, it should be fine. No need for codes to install a used head unit, just make sure to disconnect the car battery while replacing it.

[Rooster]

Fibre optic loop,

one module goes down they all do,

Need to find out and make a list of what units you have first,

ie amp, cd player, antenna unit in roof, display, phone module, sat nav

[Dieseltractor]

OK, so the only thing that has gone down is the radio which has a CD player built in and the Parking sensors which are looped through the radio. Also the Parrot kit was dead as this also goes through the amp, so I have disconnected the Parrot to exclude it from investigation.
Everything else works as it should, there is no sat nav.

[Dieseltractor]

OK, so I sent the head unit off for repair but he could find nothing wrong with it, had it on test for 3 days and no problems at all. His sugestion is that it's something on the MOST.

How do I check what it has gone down, where does the fibre loom run in the car?

I have the radio with no sub, no navigation, so I believe that just the radio, amp and aerial are on the MOST network, is that correct?

On the off chance that the MOST loom has been damaged, where does it run in the car, how does it get to the antenna in the roof, which roof pillar does it go up on? Does it go up the front windscreen pillars as these trims were removed recently/

Without a radio and more importantly without reversing sensors the car is pretty much unusable so I either need to fix this or chuck a gallon of petrol in it with a match!

Any help appreciated.

[RoscoMac]

It's the ICM .. infotainment control module...about £800 from volvo... mine went... radio had mind of its own at first...would turn up but not down. Then eventually stopped working altogether and parks. Should be able to get repaired tho.