amp comes on but no sound to sub

[Liquid Bass 10+ year member]

the sub is not blown. i took it to a local audio shop and the guy said he couldnt get it to do anything so idk what could be wrong? i looked at the board and cant see anything burnt or shorting out. it is an MTX jh1200 mono. idk if mtx will fix it or not and i havnt abused it at all. always had good clean grounds and power

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[Wingman0121 10+ year member]

Sometimes amps can poop on ya for no reason. Happened to me twice.

 

[Kangaroux 5,000+ posts]

tried checking the speaker terminals with a dmm?

 

[Liquid Bass 10+ year member]

I can hook another amp to it and it works fine.

 

[AJM511 10+ year member]

tried checking the speaker terminals with a dmm?

This.

 

[ToxicAcoustiks 10+ year member]

bench test the amp, best I can suggest.

 

[Liquid Bass 10+ year member]

bench test the amp, best I can suggest.

What does that consist of?

 

[Liquid Bass 10+ year member]

Is there anything else It could be like grounds or anything? Nothing appears to be wrong with the board.

 

[ChevyRidinLow]

did it work before? or did u just get it and it was like this? i picked up a kicker kx1200.1 that came on but didnt do anything. and it turns out pieces inside were missing but it wasnt really noticible if you dont know the ins and outs of an amp down to the smallest detail

 

[daboyfrumdabx 10+ year member]

Is there anything else It could be like grounds or anything? Nothing appears to be wrong with the board.

Of course, there's plenty of possibilities that could cause the issue. Unfortunately, it looks like you're stuck between a rock and hard place as you don't have enough knowledge to diagnose/rule out a ground issue and your local shop seems too incompetent to do so as well.

 

[ToxicAcoustiks 10+ year member]

trying it in on a battery if youve got an extra stereo laying around, I've got a setup in my garage for situations like this. Or if you've got a friend who has a stereo in his car you could put it in on his wiring.

I've got the same problem with a rockford fosgate t3002, just stopped working one day. Been to lazy to bench test it as I said above, but I'm hoping its not blown. Goodluck with yours, let us know what happens!

And did you get it this way, or did this just happen recently?

 

[macisme 10+ year member]

when you hook a sub up to it.. does it do anything? No so much sound but does the sub move at all? Is there any protection light that kicks on when you put rca's on it? You can make sure that your inputs are still working properly by putting a dmm's negative terminal on the amps + and - outputs while using the DMM's positive on the negative part of the rca input.. which is just the outer metal ring. If the dmm reads higher then .1v you probably have a bad issue. I have a similar issue with a Rockford amp that reads 30v on only the left + output from the amp. Protection lights don't always work when they should so just do as much testing as you can just use junk subs etc so you don't risk damaging anything good. Here's some more things you could try even though your protection light isn't on.. the testing with the DMM can be seen at the bottom of the page.

 

[K5BLAZER]

I am having a similar problem but my RCA read perfect on the dmm but the output side for the subs are not reading what could be the reason? Do you know any reputable shops that fix amps Near Texas?