Help, No output !
Thread Starter
50 Watt CAFz'r
Joined: Apr 2002
Posts: 58
I've been having this problem with my setup, where it can be used for maybe 30-60 minutes. This is not an overheating problem. I sent my amp in twice to get this problem repaired, and got it back with the exact same problem. They couldn't find any problems. So i figured it was a problem with the wiring. I ripped everything out and started from scratch, leaving no areas for the wires to be pinched.
It seems to play fine, then i turn off the car and come back to it later on in the day, and it no longer plays any bass.
The power light is on, and the protection light never comes on.
Hopefully someone on these forums will know how to fix this problem.
It seems to play fine, then i turn off the car and come back to it later on in the day, and it no longer plays any bass.
The power light is on, and the protection light never comes on.
Hopefully someone on these forums will know how to fix this problem.
50 Watt CAFz'r
Joined: Aug 2000
Posts: 410
Amp must be dead, so how about i do you a favour and send you $50+shipping and i'll take that 2500D off your hands 
jk man heh
If you know you have a good ground/power/remote then first off i'd check your input into the amp.
Either try running your RCA's into another amp and see if it puts out any sound, or like me take a walkman or MD player with a headphone to RCA adaptor and plug it straight into the amp (at low volume) and try running it to see if there is any sound comming out. I'd bet it has something to do with the inputs from the deck.
but double check your speaker connections as well, if your running series connection if one isn't making contact none will play.
jk man heh
If you know you have a good ground/power/remote then first off i'd check your input into the amp.
Either try running your RCA's into another amp and see if it puts out any sound, or like me take a walkman or MD player with a headphone to RCA adaptor and plug it straight into the amp (at low volume) and try running it to see if there is any sound comming out. I'd bet it has something to do with the inputs from the deck.
but double check your speaker connections as well, if your running series connection if one isn't making contact none will play.
50 Watt CAFz'r
Joined: Oct 2003
Posts: 113
Definitely check the speaker impedance.
If you are presenting a lower impedance than the amp can handle, the amp may shut down. The protection light won't come on, if the amp doesn't have impedance protection, per se. But running double the current through the componentry might be tripping something inside the amp.. it may have self-resetting breakers inside to protect against just such a misinstallation issue.
What all is wired to the amp, and how is it wired?
Another thing I'd check is that your signal source is all good.
Take the head unit right out of the equation.
Go to Radio Shack and buy a cheap length of RCA cable, something that'll reach to your front seat. Get an RCA to stereo 1/8" headphone plug adapter.
Take a portable CD player to your car, plug the 1/8" headphone plug adapter and plug it into the portable CD player. Plug the RCA cable into the adapter too. Now plug the RCA cable into your amp.
Use that for your head unit for the day, and see if the signal cuts out on you.
If it doesn't, put things back the way they were, with the head unit (that you can now suspect is faulty).
Another interesting thing would be to get a 1/8" headphone jack female-to-female jack coupler... and just wait for the signal to cut out. When it has, don't shut anything off, but unplug the RCA's from the amp, plug the RCA-to-headphone-plug adapter in there, plug the female-to-female coupler into the adapter, and plug a set of walkman headphones into the coupler, and see if you actually do, or don't, have signal coming through the RCA's.
If the amp isn't actually shutting off, it's got to be that either the amp is internally shutting itself down (ie. impedance of your speaker load is too low), or that the thing feeding the amp has stopped feeding it.
The remote and power wires are most likely fine, since you said the amp doesn't actually shut down.
If you are presenting a lower impedance than the amp can handle, the amp may shut down. The protection light won't come on, if the amp doesn't have impedance protection, per se. But running double the current through the componentry might be tripping something inside the amp.. it may have self-resetting breakers inside to protect against just such a misinstallation issue.
What all is wired to the amp, and how is it wired?
Another thing I'd check is that your signal source is all good.
Take the head unit right out of the equation.
Go to Radio Shack and buy a cheap length of RCA cable, something that'll reach to your front seat. Get an RCA to stereo 1/8" headphone plug adapter.
Take a portable CD player to your car, plug the 1/8" headphone plug adapter and plug it into the portable CD player. Plug the RCA cable into the adapter too. Now plug the RCA cable into your amp.
Use that for your head unit for the day, and see if the signal cuts out on you.
If it doesn't, put things back the way they were, with the head unit (that you can now suspect is faulty).
Another interesting thing would be to get a 1/8" headphone jack female-to-female jack coupler... and just wait for the signal to cut out. When it has, don't shut anything off, but unplug the RCA's from the amp, plug the RCA-to-headphone-plug adapter in there, plug the female-to-female coupler into the adapter, and plug a set of walkman headphones into the coupler, and see if you actually do, or don't, have signal coming through the RCA's.
If the amp isn't actually shutting off, it's got to be that either the amp is internally shutting itself down (ie. impedance of your speaker load is too low), or that the thing feeding the amp has stopped feeding it.
The remote and power wires are most likely fine, since you said the amp doesn't actually shut down.
Thread Starter
50 Watt CAFz'r
Joined: Apr 2002
Posts: 58
i have not tested my impedance. I dont know how.
I tried a different set of RCAs and tried it from another deck to my amp and it still had no output,
Speaker connections are good and deck connections for the harnass are welded.
This problem happens on both series and parallel, no output from either subs.
I'm running my amp at 8ohm (apprx 400watts) No problems with this system for the last year at 8ohm, never overheated or shutdown.
I thought it was the deck forsure, but in the other system i tried, there was no output.. leaving me really clueless.
What else is there that i can check?
It was working for like 30 minutes then went out again
I tried a different set of RCAs and tried it from another deck to my amp and it still had no output,
Speaker connections are good and deck connections for the harnass are welded.
This problem happens on both series and parallel, no output from either subs.
I'm running my amp at 8ohm (apprx 400watts) No problems with this system for the last year at 8ohm, never overheated or shutdown.
I thought it was the deck forsure, but in the other system i tried, there was no output.. leaving me really clueless.
What else is there that i can check?
It was working for like 30 minutes then went out again
50 Watt CAFz'r
Joined: Oct 2003
Posts: 113
The impedance is what speaker load you have connected..
You don't "choose" to run the amp at an impedance, you hook up a load to it.
Hook up a 4 ohm speaker to it, the amp is seeing a 4 ohm load, and will make as much power as it's supposed to into a 4 ohm load, per it's ratings.
Hook up two 4 ohm speakers to it, and the amp could either see a 2 ohm total load, or an 8 ohm total load, depending on if you wire it in parallel or series, respectively.
If your amp is only stable to a 4 ohm load, and you have a 2 ohm load hooked up to it, that could be your problem.
That's simply fundamental, and you really do need to doublecheck that.. that's not something you should be even slightly vague on, because the compatibility of your speakers with your amplifier - and even the health of your amplifier - depends on it!
You don't "choose" to run the amp at an impedance, you hook up a load to it.
Hook up a 4 ohm speaker to it, the amp is seeing a 4 ohm load, and will make as much power as it's supposed to into a 4 ohm load, per it's ratings.
Hook up two 4 ohm speakers to it, and the amp could either see a 2 ohm total load, or an 8 ohm total load, depending on if you wire it in parallel or series, respectively.
If your amp is only stable to a 4 ohm load, and you have a 2 ohm load hooked up to it, that could be your problem.
That's simply fundamental, and you really do need to doublecheck that.. that's not something you should be even slightly vague on, because the compatibility of your speakers with your amplifier - and even the health of your amplifier - depends on it!
50 Watt CAFz'r
Joined: Sep 2003
Posts: 192
Hello
If you have been overstressing the amp it wouldn't necessarily show in the beginning. The circuit board traces heat up and unglue themselves. I have repaired a few amps (and other electronics) that have had this condition none had safety circuitry (or were bypassed). When it does work again hit the amp a few times and see if it shuts off. Could even be a bad solder joint? So many possibilities.
Good Luck J
If you have been overstressing the amp it wouldn't necessarily show in the beginning. The circuit board traces heat up and unglue themselves. I have repaired a few amps (and other electronics) that have had this condition none had safety circuitry (or were bypassed). When it does work again hit the amp a few times and see if it shuts off. Could even be a bad solder joint? So many possibilities.
Good Luck J
