A1EK

For over a year now my 2004 SL350 has got the typical issues with the Comand system not working showing the 'System Unavailable' message after about 15secs then shuts off.
I have managed to get the Comand Radio to work most of the time, however it is getting harder to get it to come on. Sometimes randomly it will just start working, I have checked the following:

• Ran diagnostic through my Maxicom shows issue with MOST ring with fault code of D117 "Specified/ actual configuration of MOST ring differs" I have checked all fibre optics and they look good, I have attached optical by-pass loops one at a time.
• I have removed DVD nav unit in boot and it looks fine, my maxicom also shows it being detected.
• I have removed Becker Audio Gateway, (Q02 A220 870 1789) opened it up and checked inside, all looks visually good but it could be on its way out?
• I have removed Bose Amplifier (A230 820 38 89) opened it up and checked inside also, all looks clean and dry.
• I have checked connections and made sure they are tight and clean.
• I have by-passed the amp using the fibre optic loop and Comand starts to work, fault message goes but obviously no sound as no amp.

Observations:
I noticed that the amplifier when turning on, there is a small relay click and like wise when turning off. Therefore if I do not hear the little relay click I find the Comand system does not come on. Also there is a little computer cooling fan inbuilt on the amp, does anyone know if this is to be on all the time? At the moment it is not spinning and the Comand system is not on.
Does anyone know in the UK a repair service for Mercedes Amplifiers? as a used one is £600-700

Teem50

These people: https://www.uniquecarsound.com/comand/ are in the UK, although a long way from Glasgow, and claim to know about comand systems? I've never used them, just aware that they exist.

A1EK

Thanks for the link,