A little stereo amp help please...

[WizKid]

Sony head, alpine f240 amp. Only non-amplified sound comes through. Rep says if the amp was blown, no sound could be heard. Any ideas before I pull it out of the water & take it to the shop?

[Christian]

What do you mean "non-amplified" sound, do youmean the output is soft, or only speakers connected to the head-unit have sound?

Assuming the following;
Checked all fuse
Checked gains
Checked switches (to make sure no filters have bene changed)
Checked fader on head unti (some sonys fade the pre-outs to one side or the other)
Checked RCA's to make sure they are plugged in securely, or if using the high-levelinputs, make sure plug is in securely
Checked ground to make sure it is secure



This is a start off the top of my head

[WizKid]

All speakers are connected to the amp and the sound is soft, perhaps even softer than if the head was hooked direct to the speakers. I do have volume control but the sound acts as if the amp is passing it through from the head without amplifying it.

All 4 speakers "fire" and the sound seems properly balanced and faded - just not amplified.

I'm ignorant: tell me how to check the ground?

[Christian]

easiest way is to have volume on sofly and "wiggle" the connection at the amp and at the connection point at the boat.

Did it get soft all of a sudden, or was there an event the preceeded the softness

[BajaJEFF]

Ground is the Black wire Pete. There will be one on the head unit and a seperate one for the amp. (Special note: some amps just have a (-) connector and the installer can use any color wire)

If all your speakers are connected to the amp, then the problem would have to be with the amp.
Check fuses, verify ground is connected, make sure all 8 wires are connected for the speakers going to the amp.
You will not get electrocuted, do what Christian said, leave stereo running and wiggle the wires around.

[BajaJEFF]

Pete is this your amp?

[WizKid]

The system was installed at the end of the 2003 summer and it worked fine. The problem surfaced with the beginning of the 2004 season. The only thing electrical that was done was that I had new batteries installed.

There is a peripheral "issue" in that my windshield wiper recently started spontaneously and the switch would not shut it off. Even pulled the fuse but no help. Disconnected power to the motor which finally shut it off. Don't know if they are related issues or not.

[BajaJEFF]

Pete I thought about one more thing for you to check.

With your wipers acting up too, I would look back by your batteries and try to locate a wire that is not connected, just maybe when they switched out the batteries they forgot to hookup a ground wire.
P.S. I'm not saying to hook it up until we know where it goes.

[WizKid]

Yes, That's my amp. What I really need is that older son of yours, and perhaps his buddy - both of which are much thinner than I to rummage around in there.

I have the original manual and wiring diagram and the rep said in 15 years of doing this, he has never known of an am to blow and still pass sound.

[BajaJEFF]

I would agree. That's why I would look at:

1. Where your batteries are, see if you have a wire that's not connected.

2. With the stereo running, wiggle the wires around your amp and stereo. If the sound jumps up then you just need to figure out which wire is coming unconnected

[GVL]

I changed my batteries this year and hooked up the amp wires backward on the battery and had no subs, make sure you have a ++ and -- hookup. If its backwards check inline fuses too.

[Josh]

It could also be one of the RCA terminals or cables grounding out.
Very unlikely- but possible.

[mnfastboat]

How about a remote on switch?
I know several people have forgot about that? [smilie=071.gif]

[WizKid]

By remote switch, do you mean that turning the head on also automatically turns on the amp? yes, that is the way it is wired. And the amp does indeed light up.

It would seem I have power to the amp. Fuses have been checked. If blown, the amp wouldn't turn on, would it?

I get relatively clean sound out of the system, it's just not amplified.

Is there anything in the head unit that might be problematic?

[skeeler]

Here is my amplifier checklist I always use;
1- Check all connections; power, ground, etc.
2- Check the remote turn on to the amplifier with a volt meter. (make sure the amp is being told to turn on)
3- Plug in a totally separate audio source (Ipod or mp3 player is best). This was if it works then the problem is the head unit.

My two cents.

[mnfastboat]

from my limited expereince the power turn on is not the same as power to the amp
Main power to the amp is possible, just a remote wire actaully kicks the amp in.
I know a truck I had had been set up this way. And if I ever do a stereo in the boat that is what I want.
Still have some sound, with out the drain of the amp.
Then hit the remote turn on, and bam- Amplified sound :)

That is at least what was in one previously owned truck taht I had a system put in did. My neighbor has his car system that way also. And from what I am told is common.
Most I have seen are a blue wire to turn on the amp. I would check to see if power was coming from what you disconnected

[skeeler]

from my limited expereince the power turn on is not the same as power to the amp
Main power to the amp is possible, just a remote wire actaully kicks the amp in.
I know a truck I had had been set up this way. And if I ever do a stereo in the boat that is what I want.
Still have some sound, with out the drain of the amp.
Then hit the remote turn on, and bam- Amplified sound :)

That is at least what was in one previously owned truck taht I had a system put in did. My neighbor has his car system that way also. And from what I am told is common.
Most I have seen are a blue wire to turn on the amp. I would check to see if power was coming from what you disconnected

The 12volt power and the remote turn on are basically the same thing. They are both positive current. The remote just turns the amp on when the head unit comes on so the amp is not in the "on" position all the time. If you think this is the problem, a quick test would be to run a "jumper" wire from the remote turn on terminal to the 12v positive terminal on the amp and see if that solves your problem. Then you will know it is the head unit.