Stereo Dramas

[Parker]

Hi Guys,

I have an older Alpine head unit in my 32 GTR that has stopped working after driving over some really rough road works (not 4wd territory or anything but i had the stereo turned down whilst going through the works and when i went to turn it back up when past the works there was no sound).

The head unit still lights up, plays through a cd, finds radio stations and the sound display/equaliser is still moving but there is no sound. If you turn off the headunit and then power it back on you can hear the speakers 'click'. Because the only thing to change was going over some rought ground initially i thought a fuse or connection may have gone somewhere so i pulled the head unit out and it all looks good there, checked the fuse in the fuse box and also all good there. Then i pulled the doors apart and checked the connections into the speakers and crossovers and once again all is good there. I have an amp wired in the boot that has never had a sub hooked up to it since i've owned the car so i can't really say if anything is amiss back there, but it all looks good to my untrained eye.

I have an Alpine head unit, Focal 6' fronts with MB Quartz tweeters and 6.5' on the parcel shelf.

So has a connection come loose somewhere (i guess near the head unit as all of the speakers are out), a fuse that i cant find blown or what?

Thanks for your help.

Cheers,

Ryan.

[Baconer]

did you check if the ground was still connected?

[DRD-00F]

I would have replied quicker if SOMEONES av wasn't so boob oriented... Geeze Baconer, there are kids on here!

Are the speakers powered off your headunit, or that amp in the back? In case it isn't something simple like wiring, theres a good chance either the tiny amp in the head unit has blown, or the RCAs to the amp are gawn... either way, if you were using the head unit to power the speakers, then just buy an amp and use that to power them, it will probably still send a signal out...

If you were using the amp, check that over, it might be in protect mode after that click, or you may have lost your RCAs...

[Parker]

Speakers are powered through the head unit as the sub function on the head unit isn't being used (no sub). As for checking the earth i can't say as i noticed anything amiss when taking the head unit out but i'll put it on list of things to re-check before i go paying anyone.

I know i also have some extra wiring in the engine bay that i think is supposed to minimise interferance with the sound from other electrical items on the car (engine noise?) I know thats a cr@ppy explanation but any ideas here??

Cheers.

[DRD-00F]

Worst case scenario, move your speakers over to the amp, unless it's a mono-block just for subs, then you will have to buy a different one... You will notice a HUGE change in both sound quality and volume if you get a decent amp onto the speakers

As for the actual problem, you say everything works, it plays through CDs and you can tell it is reading the data on the visual EQ... if you then hook up a speaker to it, and check that your levels and faders are alright (which unless you changed them they should be) and there is no sound, then the amp in the headunit is farked one way or another... could be a lost connection, dry joints, fried board... anything really... if it is under warranty, you will probably have to take it back... if it isn't and you want to keep it, you can still pay to have it repaired, but if it is a cheap head unit, it may not be worth it

K home time nao

Double check everything... it's often something silly, but I just skipped all the obvious stuff

[Chris Rogers]

if you hear a click then that is the amplifier going into protection- you have a short somewhere. pull a speaker at at time with the radio on low volume. that will show you what went wrong.

[Parker]

Thanks guys, a few things to check over the weekend or maybe this afternoon if all goes well.

Gotta love Sau.

[Hotr34]

Speaker short run new wires for speakers or find the short....

[Parker]

Pulled the power to the cross overs on both front doors one at a time and still had the click. Moved onto the rear speakers and noticed that they actually go to the amp (my bad, i thought it was all through the headunit). Wiring goes from left and right rear speakers to the L & R on the amp with another set of wires that run through the vehicle with the RCA's to the rear of the head unit (i.e. both the speaker + & - and the other wire + & - in each of the L & R socket on the amp). Disconnecting the rear speakers and the other wires from the amp leads to a loss of the click but no sound at all.

Amp is an Axis "Mosfet 300watt 2 channel bridgeable power amplifier"

Earth is still intact and happy. The amp's 30amp fuse is still good.

I'm lost, are the other wires that go to the back of the amp (other than the rear speakers) providing the signal for the rear speakers or the fronts?

[Chris Rogers]

brand of amplifer. lights on amplifer? protection light -on?

[Parker]

It's an Axis amp, power light is on, protection light is not.

Headunit is an Alpine CDM-7874EB, i've tried the reset out of desperation and suprise suprise no change. The noise i describe as a 'click' when turning the headunit on or off seems to come from the speakers themselves.

[Chris Rogers]

ok elimination time.take a speaker off the amp and if the radio has speaker outputs tie the speaker to it. sound? no sound? that will rule one of them out .