Radio powers up, then turns off on its own. Anyone know what causes this?
Thread Starter
Member
Joined: May 2015
Posts: 241
Likes: 17
From: Houston, TX
2006 E55 AMG, 2018 Audi Q7, 2005 Porsche Boxster S, 1930 Model A Hot Rod, 744HP 1965 Shelby Cobra
Radio powers up, then turns off on its own. Anyone know what causes this?
I turn my Command unit on, the screen illuminates, and after a few seconds it powers down. I was going to replace the head unit, but the car stereo guy I was talking to who does a bunch of these scars ays that this may not be an issue with the head unit, it could be an issue with the infrastructure it's connected to, and a new radio may well just do the same thing. Do any of you guys have any experience with this and an idea what might be going on here?
Junior Member
Joined: Sep 2018
Posts: 18
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S550 E500 E350
Likely a MOST ring issue over the comand unit being bad. Need to see actual vs specified values for ring components. Most common is something gets wet left side trunk and breaks the fiber optic ring. My nav unit went bad this year and caused the same symptoms. Just loop it out re-code and good to go.
Thread Starter
Member
Joined: May 2015
Posts: 241
Likes: 17
From: Houston, TX
2006 E55 AMG, 2018 Audi Q7, 2005 Porsche Boxster S, 1930 Model A Hot Rod, 744HP 1965 Shelby Cobra
I bought a fiber optic loop on Amazon for troubleshooting. My understanding after attending YouTube University on this issue is that I can loop out components one by one to see when the radio head will finally turn on normally, and that will identify which one went bad. I thought that I could just leave the loop in place to continue to use the radio with the faulty component looped out, but apparently if i understand what was written above correctly, I need to have the car re-coded? Would I need to go to a dealer to have this re-coding done? I usually try to avoid the dealer at all costs due to the stratospheric prices they charge.
The nav unit on my car failed years ago, and because it's so primitive I never bothered doing anything about it. Everything has worked fine with it failed up to this point for all this time, so I'm guessing it's probably not the nav unit. What has changed is that along with the head unit powering up and subsequently shutting down spontaneously moments later, the CD changer door will no longer open as it always has done flawlessly in the past. I guess I need to figure out the chicken and the egg - has the head unit failed because the CD changer door operation has failed, or is the CD changer door no longer working because the head unit failed.
The nav unit on my car failed years ago, and because it's so primitive I never bothered doing anything about it. Everything has worked fine with it failed up to this point for all this time, so I'm guessing it's probably not the nav unit. What has changed is that along with the head unit powering up and subsequently shutting down spontaneously moments later, the CD changer door will no longer open as it always has done flawlessly in the past. I guess I need to figure out the chicken and the egg - has the head unit failed because the CD changer door operation has failed, or is the CD changer door no longer working because the head unit failed.
Junior Member
Joined: Sep 2018
Posts: 18
Likes: 2
S550 E500 E350
I always change the coding for the most ring so the car knows exactly what it’s looking for. Easiest thing is to find someone local with a star unit to avoid the dealer. I always lean towards a little diag before pulling panels or components.
Was the nav unit looped out when it failed?
CD changer is a part of the most ring so likely affected by whatever is taking the ring down unless the changer itself is what failed.
Was the nav unit looped out when it failed?
CD changer is a part of the most ring so likely affected by whatever is taking the ring down unless the changer itself is what failed.
Thread Starter
Member
Joined: May 2015
Posts: 241
Likes: 17
From: Houston, TX
2006 E55 AMG, 2018 Audi Q7, 2005 Porsche Boxster S, 1930 Model A Hot Rod, 744HP 1965 Shelby Cobra
The nav unit was not looped out. It stopped working, and everything else worked fine for the next 6 years with it just failed and left as is, so I didn't bother looping it. I never even knew about the loop thing until my head unit stopped working a few weeks ago and I started looking all this stuff up on YouTube. The funny thing is, I do own a STAR unit, but I don't know how to do coding. I don't need to look for a STAR unit, I need to look for someone who knows how to use it properly! 
