Sl55 no sound from bose system

[Robjit]

Hi all - I've recently acquired a 2003 SL55 which had a few things needed to bring up to scratch. I appear to have no sound from the comand unit. I was told that it might be a good idea to check the most fibre cable network but can't find a loop that will fit.

Having took apart the rear to get to the modules I found a silver unit that looks like the back of a radio unit with the plugs taken out. I have plugged it all back but noted it has 3 set of gold plated phono plugs with no wires for it?

I also took out the CD changer to release the CD magazine, but still have no sound.

Can anybody advise? Many thanks.

 

[LostKiwi]

Does your car have Bose?
If so it won't be MOST as that didn't appear until 2004.
If it has fibre loops it will be the earlier D2B optical system which is not compatible with MOST.
The unit you've found is the Audio Gateway.

 

[ianplymouth]

mine was the amplifier, it wasn't sending out the data down the fibre optic cable.
replaced it with a used unit from Ebay been working fine for years now.

 

[Robjit]

Car has bose and yes it has the fibre loops like the earlier 2001 R129 sl...

Any ideas where to start with diagnosing it to find out why there's no sound?

 

[Robjit]

mine was the amplifier, it wasn't sending out the data down the fibre optic cable.
replaced it with a used unit from Ebay been working fine for years now.

How did you diagnose it? I don't want to buy bits unless I know its needed

 

[Robjit]

Does your car have Bose?
If so it won't be MOST as that didn't appear until 2004.
If it has fibre loops it will be the earlier D2B optical system which is not compatible with MOST.
The unit you've found is the Audio Gateway.

Car has bose and yes it has the fibre loops like the earlier 2001 R129 sl...

Any ideas where to start with diagnosing it to find out why there's no sound?

 

[LostKiwi]

If I recall correctly the Bose amplifier is in the boot. That would be my first place to look given the propensity for these cars to leak...

 

[Alfie]

That looks like the early TV tuner. Its common for it to fail and will cause all sound to stop.

What you can do to test it is to remove the fibre cable from the tuner and dismantle the plug to reveal the two ends.
Make sure you remove enough tape from the fibre pair to carefully loop one end to point into the other. Itll help if you have someone hold these together whilst you turn on the Comand to see if it fixes it.

Do not cut or kink the fibre cables.

If it fixes it, get some shrink wrap to hold the two ends together. Then splint the join with something and tape it all up.

 

[Robjit]

That looks like the early TV tuner. Its common for it to fail and will cause all sound to stop.

What you can do to test it is to remove the fibre cable from the tuner and dismantle the plug to reveal the two ends.
Make sure you remove enough tape from the fibre pair to carefully loop one end to point into the other. Itll help if you have someone hold these together whilst you turn on the Comand to see if it fixes it.

Do not cut or kink the fibre cables.

If it fixes it, get some shrink wrap to hold the two ends together. Then splint the join with something and tape it all up.

That sounds great.. But when I look at the plugs that go into the TV tuner, there is no fibre cables anywhere near it... Just the two plugs... One with two power cables and one with a load of wires... There is a third plug with 4 round connectors at the right side... But that doesn't look like fibre cables and there's 4 of them?

 

[LostKiwi]

I think the 4 connectors on the right side are antenna connections.

 

[Alfie]

That sounds great.. But when I look at the plugs that go into the TV tuner, there is no fibre cables anywhere near it... Just the two plugs... One with two power cables and one with a load of wires... There is a third plug with 4 round connectors at the right side... But that doesn't look like fibre cables and there's 4 of them?

Okay, its a very early TV tuner. Try the same procedure on the CD changer, then the phone controller. Worth checking for dampness under the Bose amp which I think on your car is under the CD changer.

 

[ianplymouth]

How did you diagnose it? I don't want to buy bits unless I know its needed

It was diagnosed by a local indy, he had a tool that he plugged the optical cables into to find the fault.

 

[Robjit]

It was diagnosed by a local indy, he had a tool that he plugged the optical cables into to find the fault.

I need a decent indie up here in leeds... I'm gonna try to find one but if anyone knows a good one near me- it would be appreciated!

 

[Blobcat]

I need a decent indie up here in leeds... I'm gonna try to find one but if anyone knows a good one near me- it would be appreciated!

Prestige in Ossett have some good reviews, I’ve talked to the owner but not used them

 

[Robjit]

So I've checked all the fibre optic loom and after disconnecting tried to face the wires to each other but nothing... I tried all the connections one by one - isn't there supposed to be some light coming out of them? I have nothing coming out of any of them and even took out the radio in the dash to check it hadn't become unplugged here...

I also changed the bose amp as I was told this is usually the main culprit - but still nothing!!

Anybody have any ideas as to what next? Am I right in saying there should be light coming out of the fibre loop??

 

[Robjit]

There's no signs of damp there either, so I'm stumped atm..

 

[Viscount]

I lost audio shortly after getting my 350SL (2003) with Bose. It was the fibre connector at the rear of the main COMAND unit. Pushed it back in and never failed since (worried I've said that now....)

 

[Robjit]

I lost audio shortly after getting my 350SL (2003) with Bose. It was the fibre connector at the rear of the main COMAND unit. Pushed it back in and never failed since (worried I've said that now....)

You talking about the main head unit in the dash? I tried that too..

 

[LostKiwi]

How did you check for light?

Best way is to use a phone camera to check.

 

[Robjit]

How did you check for light?

Best way is to use a phone camera to check.

I just used my naked eye as I assumed it would be obvious like on my dad's R129 SL... Am I wrong in assuming this?

And do I need to turn the power on and off each time I try to loop a connection??