No warning tones, No radio sound, No bluetooth & No HUD - Modules?

[12X535D]

Hi everyone! I would greatly appreciate any input and advise on the subject matter.

2012 BMW X5 35D w/Comfort Access

After reconnecting the battery (replaced the rear air compressor), I ran into all sorts of issues that didn't previously exist. I currently have:

• No Warning Tones
• No Radio Sound - radio is on, stations are listed and CD ejects and loads
• Bluetooth doesn't work - No telephone connection
• No HUD - cannot activate on settings or by pressing the button by the headlights

* I can adjust certain settings and the Navigation works just fine.

I purchased a fibre optic loop, and began by plugging it into the fibre optic cable that leads into the Amp and then the TCU (I believe it is the TCU...sits next to the Amp in the rear left panel) and they seem to be working just fine (both have red blinking lights). There's one other component that is tiny with a pink connector, but from what I've heard, it is the satellite module or something to that effect (doesn't seem to have a fibre optic cable). I'm now trying to figure out what other modules are tied into the same fibre optic system (circle...loop), so I can continue testing.

I've also read somewhere online that the MOST connector located on the passenger side footwell area is also in the loop, so I check...pulled both apart and placed them together then inserted the loop I purchased...nothing happened, but I did notice that there wasn't a red light or blinking red light. If this is an actual fibre optic line, then I have to assume the problem lies there, but what does this MOST connector connect to and where exactly under the dash is it?

Please provide any input that can help me find the issue. I've been going at this for a while now...started with faulty codes caused by replacing the rear air compressor and then the leveling system not calibrating correctly.

2012 BMW X5 35D w/Comfort Access

Thank you in advance!

Oh...I've checked all the fuses...all good, but some areas aren't getting any power. I'm not getting the SOS malfunction light. Also, I forgot to mention that at one point I got fed up and took it to a local BMW indy that has been in business for over 40 years. They completed a diag and told me that the TCU, Amplifier or HUD Modules may be the issue...not all three, but that something got fried, but they can't pinpoint it. They wanted to charge $100 an hour to pinpoint the problem and I needed to leave it overnight. I'm sorry, but I prefer to figure it out on my own than to spend $1000 on pinpointing the problem and then as he mentioned, an Amp is an extra $1000! Crazy!