# amp powers up but no output-how to test?



## cadaver (Sep 17, 2006)

i got a small amp for free and i just installed it, but there is no output. how would i go about testing if its the rcas or the speaker inputs?


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## Quiet_Vette (Jan 11, 2008)

Do you have a Digital Multi Meter?

Okay, power up the head unit and make sure the amp is on but not in protect. Usually a red LED will indicate protect.

Using the multi meter, test the 12V and ground terminals to make sure they are secure. Then, test the remote wire terminal and the ground for voltage.

If you get nothing, then there is a problem with the remote signal before it even gets to the amp. If it has voltage, move on to the output terminals.

Do you have speakers or subs connected? Test the terminals across the POS and NEG to see if you have voltage that would be going to the driver. If not, check the fuse again. If the fuse is fine you probably have a bad amp.

If you have power to the speaker, then try a different speaker.

Make sure you have the POS and NEG in correct phase.

Don't feel bad, I have gotten free bad amps before too.


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## Oliver (Jun 25, 2007)

Give it to someone else


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## MarkZ (Dec 5, 2005)

Try another source (ipod?).


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## cadaver (Sep 17, 2006)

Do you have a Digital Multi Meter?

Okay, power up the head unit and make sure the amp is on but not in protect. Usually a red LED will indicate protect.

Using the multi meter, test the 12V and ground terminals to make sure they are secure. Then, test the remote wire terminal and the ground for voltage.

If you get nothing, then there is a problem with the remote signal before it even gets to the amp. If it has voltage, move on to the output terminals.

Do you have speakers or subs connected? Test the terminals across the POS and NEG to see if you have voltage that would be going to the driver. If not, check the fuse again. If the fuse is fine you probably have a bad amp.

If you have power to the speaker, then try a different speaker.

Make sure you have the POS and NEG in correct phase.

Don't feel bad, I have gotten free bad amps before too.

its a rather old amp, so the red light it shows is for power. as far as the remote wire, it was the first in the chain and the other items got power, so im not sure there. i took the base off of it tonight, but didnt see anything severely wrong, but then again i honestly wouldnt know what to look for. when you say test power across pos and neg, what do you mean?(put the pos and neg test leads in their respective locations?) im not even sure this amp has a fuse, its a 15x2 amp thats almost as big as a box of kleenex. also, if the fuse was bad, wouldnt it refuse to power up?


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## Ge0 (Jul 23, 2007)

cadaver said:


> when you say test power across pos and neg, what do you mean?(put the pos and neg test leads in their respective locations?) im not even sure this amp has a fuse, its a 15x2 amp thats almost as big as a box of kleenex. also, if the fuse was bad, wouldnt it refuse to power up?


Check DC voltage between the positive and negative speaker terminals for each channel. No input signal, no speaker connected. It should be very low (say under 100mV). If it jumps up into the voltage range at, or higher, than your battery then an output is blown.

Next, provide an input to the amp. Try a CD burned with a 120Hz test tone. Set your voltage meter up to measure AC voltage. Slowly crank up the volume on your source and look for a rising AC voltage on your meter. What do you find?

Chances are such a little amp uses IC based preamp-output devices vs. discrete circuitry. This one should be fairly simple to diagnose. Pictures of the internals would be nice...

Ge0


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