So, I am going through the MMI/Audio issues which I have. The car has the following fitted:

Sat Nav - map shows, directions on screen no audio.

CD Multichanger - loads CD's and changes Cd's. No audio - CD's won't play.

Radio - Its receiving station signals. No audio.

I have changed the MMI control in the centre console and have more functions than I had at the start of this journey. Could the issue lie with the amplifier?

TIA.

Yep it could be the amplifier. But I'd recommend a diagnostic check to see if any fault codes flag up 

Sounds like the Amplifier issue to me.

The amp as far as i remember is in the rear 1/4 panel behind the boot linings.  theres 2 connectors on it, one small square (white) and the other is a long brown connector with a locking pin  on one end and a hook on the other that holds it in place!  Should be fairly easy to remove but without it being in the car i dont know how your going to test it! 
Its possible that one of the connectors has come loose and thats why your not getting any sound, or maybe you have a blown fuse / broken wire on the line to the amp.

 

 

I had a look in the rear panel and yes, there is the amplifier. There is one large connector, held in place with the clip and.........

There is a socket on the Amp for a connector, but no connector visible.

I have found two brown wires, with a connector which could fit the amp, but, they are currently connected together with what looks a professional loop loom. When I disconnected this, one of the pins started flashing red at me. I decided that the car is haunted and put the connector back in lol.

I'm going to have a better look, as there are a few bolts missing - as if the whole rack has been removed and there is a connector hooked down the back of everything.

I have an Amp arriving on Wednesday.....

 

is yours a BOSE system or what one is in your car?

Theres a fairly common issue that the Rear Window Washer, leaks and then corrupts and corrodes the amplifier boards.
What i would suggest is while your in there, seal up any of the joints etc where the water can leak from or reroute the  washer line 

 

One picture (162932) showing the connector which could fit in the amplifier, with the loop fitted and the other picture (162951) shows the pin flashing red.

I got brave and plugged it in to the Amp and absolutely nothing happened - blank screen!

I will watch the video you have kindly sent later. I do have an issue with water - the rear window seal above the quarter panel is damaged and the sound proofing in the well of where all of these gizmos live is damp. Lol - the washer bottle does empty itself, but I have no smell of washer fluid in that area.  

3 hours ago, Hammie1982 said:

is yours a BOSE system or what one is in your car?

Theres a fairly common issue that the Rear Window Washer, leaks and then corrupts and corrodes the amplifier boards.
What i would suggest is while your in there, seal up any of the joints etc where the water can leak from or reroute the  washer line 

 

Its a "Becker" (I think!)