Head unit stopped working

[joeyjojojr]

Hi guys, this is my first post on this forum and I am in need of some assistance. I am not too familiar with car stereo installation and in fact did my first install a little over a month ago. I put in a new Alpine 9833 along with new front and rear speakers. I have yet to put in any sort of amps or subs due to lack of funding at this point. Everything was working great for about 2 1/2 weeks, but then when I drove my car again about a week later there was no sound at all coming from my speakers. I had done nothing to my car in that one week period. The head unit turns on and appears to playing the cd but there is no sound whatsoever. The preamp outputs still seem to work though because I tested them with some of my home theater equipment. In addition to that, when I hook up the factory radio, everything seems to work just fine. I think that maybe the connections on the rear speakers could have caused a short so I unhooked all the speakers and tested them one by one on the head unit, trying making sure there were no shorts, but still nothing seemed to work. Is it possible somehow fried the internal amp of the head unit, because I thought it would have some sort of protection against that. Do I just need to reset the head unit somehow or is it possible I blew a fuse somewhere. Sorry for the long post but I am terribly frustrated at this point and would appreciate any assistance at all. Thanks.

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[M@nJo 10+ year member]

open the deck out and check all the wires behind the harness. could be the remote, speaker, ground, anything.

btw, when you installed the head unit, did you use crimp caps, not electrical tape to splice the wires?

 

[joeyjojojr]

open the deck out and check all the wires behind the harness. could be the remote, speaker, ground, anything.
btw, when you installed the head unit, did you use crimp caps, not electrical tape to splice the wires?

When you say open the deck out, do you mean just take it out of the dash or actually open up the head unit to look at the circuitboard, cd player, etc?

When I installed it I used wire harnesses and used crim caps on most of the wire connections except for the constant and switched power wires because they were too large for the crimp caps. Instead I soldered those connections and covered them with electrical tape which I assumed would be okay. Since I've been having trouble I've gone back and redone all the connections, but nothing makes a difference.

 

[M@nJo 10+ year member]

meant by taking it out just enough so u can see the wires behind it, not the actual deck, sorry for misconfusion.

solder and crimp caps are fine. im lost as well. all i can think of are maybes/assumptions/guesses. do you think maybe a wire was loose and when you drove over a dip, it could've bounced off?

have you checked your speakers to see if the wires are still connected as well? the rears shouldnt take long, but the fronts may since there behind doorpanels.

goodluck man

 

[dkc62 10+ year member]

I had this happen on my very first cd player and it was because the cd player wasn't fused.

 

[joeyjojojr]

meant by taking it out just enough so u can see the wires behind it, not the actual deck, sorry for misconfusion.
solder and crimp caps are fine. im lost as well. all i can think of are maybes/assumptions/guesses. do you think maybe a wire was loose and when you drove over a dip, it could've bounced off?

have you checked your speakers to see if the wires are still connected as well? the rears shouldnt take long, but the fronts may since there behind doorpanels.

goodluck man

Thanks, but yeah, I'm thinking that the bolts came loose on the rear speakers causing the contacts and exposed part of the wire to come in contact with a metal part of the car. I've already checked all the wiring to the speakers and they're all still connected correctly and nothing is exposed any longer.

I just found this at BCAE :

"Note:

On "high power" units, the internal audio amplifier will be instantly damaged if a speaker output wire is allowed to contact anything except a speaker terminal, even if the volume is not turned up. Be sure that there is no power to the unit when making any connections. This link explains why the outputs will be damaged if they contact ground."

After reading that I'm afraid that if my speaker did cause a short, then the H/U may be irreparably damaged (at least beyond what I can do.) Anyone out there that can confirm or deny my suspicions?

 

[joeyjojojr]

I had this happen on my very first cd player and it was because the cd player wasn't fused.

What exactly do you mean when you say it wasn't fused and did you find a way to fix it?

 

[KaeZoo 10+ year member]

Thanks, but yeah, I'm thinking that the bolts came loose on the rear speakers causing the contacts and exposed part of the wire to come in contact with a metal part of the car. I've already checked all the wiring to the speakers and they're all still connected correctly and nothing is exposed any longer.
I just found this at BCAE :

"Note:

On "high power" units, the internal audio amplifier will be instantly damaged if a speaker output wire is allowed to contact anything except a speaker terminal, even if the volume is not turned up. Be sure that there is no power to the unit when making any connections. This link explains why the outputs will be damaged if they contact ground."

After reading that I'm afraid that if my speaker did cause a short, then the H/U may be irreparably damaged (at least beyond what I can do.) Anyone out there that can confirm or deny my suspicions?

You're probably okay. Most head units include protective systems to shut off the amplifier when a speaker wire is grounded; that's why you didn't hear sound from any speaker although only one may have had a problem. If your head unit is working fine now, it's probably undamaged.

 

[joeyjojojr]

You're probably okay. Most head units include protective systems to shut off the amplifier when a speaker wire is grounded; that's why you didn't hear sound from any speaker although only one may have had a problem. If your head unit is working fine now, it's probably undamaged.

Well it's almost working fine except there's still no sound from my speakers, haha. Sorry if my last post made you think it was working once again. If the internal amplifier just got shut off do you know of a way that I can get it turned back on?

Also, I've read in other posts of people replacing the fuse on the HU. Does that mean they're replacing the fuse in the car that controls the HU or is there a fuse physically on the HU somewhere because I can't seem to find one.

 

[mobileaudio219 10+ year member]

I'm willing to bet its the head unit. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[Zach85 10+ year member]

Well it's almost working fine except there's still no sound from my speakers, haha. Sorry if my last post made you think it was working once again. If the internal amplifier just got shut off do you know of a way that I can get it turned back on?
Also, I've read in other posts of people replacing the fuse on the HU. Does that mean they're replacing the fuse in the car that controls the HU or is there a fuse physically on the HU somewhere because I can't seem to find one.

There's a fuse on the back of the head unit. I was gonna say, check the fuse behind the head unit. Usually that controls the speaker output, from what I've been told. I've seen it happen where someone's CD Player went "dead" because no sound was coming out, but all it needed was a new fuse on the back of the head unit. Take the unit out of the dash, and around where the wires go into the cd player should be a fuse that you can easily pull out and replace. If it blows again soon, try going up 5 amps. I'm assuming it's 15 amps, as most, if not all, units are, so you can try 20 amps, but ONLY if the 15 blows again soon. It shouldn't cause a problem, since 5 amps isn't a lot. but you shouldn't go any higher than 5 over the recommended rating. Just from my past experience. If you go with 20 amps, you do so at your own risk though.