Car stereo mysterious goes silent

July 28, 2010 7:11 AM

While driving into work yesterday, the stereo in my car mysteriously stopped working. I was listening to NPR, then ... nothing ... just silence. Help me troubleshoot this problem, or suggest a solution for getting it fixed.

At first I thought it was a problem with the radio station, because the unit was still turned on, all the buttons fully functional, and aside from the lack of sound it appeared to be working fine. Then I tried another radio station and nothing. I tried turning up the volume, both with the volume knob, and with the steering wheel control. Still nothing. I tried playing my MP3 player through the auxiliary jack and that didn't work either. I even tried playing a CD, flipped through the tracks, but nothing there. My final attempt was a little bit of gentle percussive maintenance, again to no avail. I'm now in Day 2 of radio silence.

The unit is a Harmon Kardon factory-installed on a 2003 Mini Cooper S. I've read through the owner's manual and cannot find any additional troubleshooting or technical information that might be helpful. I'd really love some advice on troubleshooting that may enable me to fix it myself, or recommendations on a type of repair service that would help me avoid taking it to a dealer. Thanks!

posted by slogger to technology (13 answers total)

When this happened to me I had two reasons for the failure. 1 was that the speaker wire got cut by my seat when I was moving the seat up and down. The other was that the fuse for the amp blew out. If it's the wire the fix will be harder because you'd have to find where it got cut, but they're both easy to take care of yourself.

When I went to have it looked at when it was the fuse one time it was going to cost $30 to have it looked at just to find the problem.
posted by theichibun at 7:15 AM on July 28, 2010

Can you take the unit out of the dashboard? Since it's reasonably current, it should be connected by a pair of ISO plugs. The one with the little tooth in the middle is the speaker connector, check that it's firmly seated. This page says you can use a small battery to test the speakers (and the cable path leading to them) if you're feeling adventurous.
posted by Dr Dracator at 7:34 AM on July 28, 2010

Same thing happened to me once, right before a 2.5 hrs drive. Brutal! Anyway, it turned out to be a simple fuse replacement to fix it. Just look through your car's owner's manual, and see if you can find the pages on the fuse box, and find the ones for the stereo... usually the little fuse box even has a replacement fuse or two, so it should be a free fix if that is the problem!
posted by Grither at 7:39 AM on July 28, 2010

Dr Dracator: There's nothing visible on the faceplate that makes me think I can easily remove the component. With that, I'm pretty much an idiot when it comes to anything related to electronics (and I'm definitely not the "adventurous" type in this realm).
posted by slogger at 7:53 AM on July 28, 2010

Fuses aren't adventurous at all. You look through the manual, figure out which one/ones run(s) radio stuff, and pull it out to check. If you're not comfortable then anything beyond that is worth taking it to a shop. But they're most likely going to have a minimum charge.
posted by theichibun at 8:04 AM on July 28, 2010

Is there a separate amp for the speakers somewhere? If so, it's possible it's on a separate fuse from the head unit. Get thee to the fuse box.
posted by pjaust at 8:12 AM on July 28, 2010

I'd check your manual to see where your amp and stereo fuses are, and check them. This sounds a lot like a fuse blowing to me. Most cars have at least one spare fuse that you can use to test, and if it is the fuse you can just go to an auto parts store to buy new spares.
posted by BZArcher at 11:00 AM on July 28, 2010

Were you able to see the digital display? Based on your description of being able to change CD tracks and flip it to AUX mode, it sounds like the stereo still has power and it seems unlikely that it would be a fuse issue, as that would most likely render the unit completely dead and not give you any kind of visual display feedback.

I'd check and see if there is an amplifier somewhere in the car, perhaps under your seat or in the trunk. That failing could explain why you lost all your speakers at once, but still have power going to the unit.
posted by quin at 1:40 PM on July 28, 2010

pjaust, quin: The stereo itself is still receiving power and functions normally aside from the lack of audio output. I don't know if the system has a separate amplifier. Checking the fuses will definitely be my first step when I get home from work tonight.

theichibun: re adventurousness, I was referring to Dr Dracator's recommendation to pull the unit out of the dash or checking the cable path to the speakers. I'm very hesitant to start taking things apart that I'm unsure I can put back together.

If I find out it is not a fuse, does anyone have a recommendation for proceeding with repairs?
posted by slogger at 2:28 PM on July 28, 2010

Well, after seeing that you clarified that the thing looks like it's working I'm going to say that it's most likely a blown fuse to the amp or busted speakers. You have an amp somewhere in the car. It might turn into an adventure to find it.
posted by theichibun at 4:47 PM on July 28, 2010

Let's see.. Do you still get the door ajar/seat belt warnings through your speakers, or nothing at all? Does the '03 have the same sort of onboard computer as the '07 and later models? I know that people mucking around with their stereos in later minis have managed to cause it to throw an error to the computer that amounts to "help, help, I can't see the back half of the car!" I only test drove an R53 once, so I can't remember how much different the tach display is - the later models get a big ! on them to warn about non-fatal errors.

Judging from http://www.realoem.com/bmw/showparts.do?model=RE33&mospid=48021&btnr=65_0707&hg=65&fg=25 the HK amp is buried in the boot under the right hand access cover. Something may have gotten disconnected on that. Unfortunately, it could be either the head unit or the HK amp or the power for either. If you really get stuck, there's a dedicated enthusiast forum at http://northamericanmotoring.com/ who know the wiring for the car from top to bottom.
posted by Kyol at 10:20 PM on July 28, 2010

Thanks for all answers. There's an interior fuse box that had two fuses for the stereo -- one 5 amp and one 15 amp. Unfortunately replacing both did nothing to fix the problem. Incidentally, it was the 15 amp fuse that disabled the receiver, but I didn't notice anything different about the stereo when I removed the 5 amp fuse.

Thanks for the links and info, Kyol. Maybe I'll take a look at the amp to see if there are any loose connections. To answer your question, I'm still getting audio warnings for things like leaving the keys in the ignition with the door ajar, but I don't know if that sound comes through the speakers. I don't get any warning lights on the tach or speedometer displays, so it doesn't appear that the car thinks there's anything wrong. I'll check out that North American Motoring forum and see if there's anything there.
posted by slogger at 6:29 AM on July 29, 2010

Just a follow-up for posterity...

I found several threads on the North American Motoring site that Kyol provided that diagnose the problem as a bad power amplifier and outline how this is a very common problem among first generation Mini Coopers with the Harman Kardon sound package. (This is just one of many threads discussing the issue.) Most solutions involve replacing the amp, either buying one used for few hundred dollars and installing it yourself, or paying a dealer upwards of $1000 to install a new one. A third option is to completely replace the entire stereo system, including head, amp and speakers with an aftermarket system.

As for me, I'm taking my car to the dealer to confirm the diagnosis, but not sure what I'll do after that. I have a hard time choking down a thousand bucks on my seven-year-old car for something as non-essential as a stereo system.
posted by slogger at 6:59 AM on July 30, 2010