# Channel going on & off on NVX amp



## Gregavi (Nov 20, 2017)

Hi,
I have a NVX JAD900.5 amp that I have had for about 3-4 years. It sounds good but sometimes the front channels turn off randomly. They come back on sometimes within minutes and sometimes it takes up to 1/2 hour before they come back on. I say they go on and off randomly because it has nothing to do with the amp getting overheated. First off, it happens sometimes when the system is turned on initially and sometimes it happens after the system has been running for a while. Also, if it were an overheating issue, I believe the entire amp would shut down instead of just the front channels. I'm asking for help in diagnosing this issue. Any help/advice is appreciated.
Thanks in advance.


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## gijoe (Mar 25, 2008)

Intermittent issues are almost always related to a poor connection. You need to check every wire for a snug connection at both ends of the path. Make sure that they aren't shorting somewhere, they could be lose at the amp, or the source, they could be pinched somewhere, the RCA's could be grounding against metal. Check every single connection first and foremost.


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## Gregavi (Nov 20, 2017)

gijoe said:


> Intermittent issues are almost always related to a poor connection. You need to check every wire for a snug connection at both ends of the path. Make sure that they aren't shorting somewhere, they could be lose at the amp, or the source, they could be pinched somewhere, the RCA's could be grounding against metal. Check every single connection first and foremost.


That would make sense if the entire amp was going off/on intermittently, but why would only the front channels, and not the rear, be effected if it were a poor connection? Unless the poor connection was the RCAs to the front side of the amp, which I have checked and that doesn't seem to be the problem.


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## gijoe (Mar 25, 2008)

There are RCA’s and speaker wires, right? Those not only plug into the amp, but into the speakers and the source. The bad connection might not be at the amp.


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## bnae38 (Oct 3, 2015)

Switches and pots could use a good blast of deoxit, can't really do the pots though.. sealed up good. Got a 800.4 in front of me. Work the switches back and forth many times after..


Haven't seen issues with them personally, but plenty of times on other amps...

Can get a little bottle for 10 or 15 bucks on amazon.


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## Gregavi (Nov 20, 2017)

gijoe said:


> There are RCA’s and speaker wires, right? Those not only plug into the amp, but into the speakers and the source. The bad connection might not be at the amp.


(I should have said in the the opening post) I have checked the RCA and speaker wire connections and they are solid. I have not however checked the power/ground connection to the amp for the reasons I said (because only the front half goes on/off). It has to be something in the amp itself based on my knowledge. The same thing happened with the same amp in my previous system using the stock head unit. I thought it was something wrong with the stock unit but now it seems clear that it is the amp. I have even gone from using the amp in 5 ch mode to bridging it to 3 ch. In the 5 ch mode the front would go on/off and in bridged mode the left ch (in bridged mode the front/back becomes the left/right) is going on/off.


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## Gregavi (Nov 20, 2017)

bnae38 said:


> Switches and pots could use a good blast of deoxit, can't really do the pots though.. sealed up good. Got a 800.4 in front of me. Work the switches back and forth many times after..
> 
> 
> Haven't seen issues with them personally, but plenty of times on other amps...
> ...


Can the blast of deoxit be done without taking the amp apart or the cover off, or can I just spray it into the switches from the exterior? I have a spray can of contact cleaner that I assume is the same as deoxit called PureTronics.


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## miniSQ (Aug 4, 2009)

Gregavi said:


> Can the blast of deoxit be done without taking the amp apart or the cover off, or can I just spray it into the switches from the exterior? I have a spray can of contact cleaner that I assume is the same as deoxit called PureTronics.


yes you can try spraying it right into the contacts. Do you have seperate switches that control front and rear channels? I had this issue on a JL 300/4 amp and deoxit fixed the amp for me.


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## bnae38 (Oct 3, 2015)

Gregavi said:


> Can the blast of deoxit be done without taking the amp apart or the cover off, or can I just spray it into the switches from the exterior? I have a spray can of contact cleaner that I assume is the same as deoxit called PureTronics.


Better strategy might be to wiggle switches and see if audio cuts in/out first.


I think you can spray them from the outside.


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## gijoe (Mar 25, 2008)

You don't have the amp wired to too low of an impedance do you?


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## Gregavi (Nov 20, 2017)

gijoe said:


> You don't have the amp wired to too low of an impedance do you?


I have it wired according to the manual for "bridging" and had it wired according to the manual for 5 ch.
Don't see how that's the problem.



miniSQ said:


> yes you can try spraying it right into the contacts. Do you have seperate switches that control front and rear channels? I had this issue on a JL 300/4 amp and deoxit fixed the amp for me.



It does have a "Stereo-Bridged-4 Channel" switch. I will play with that and spray it with contact cleaner and see if that solves it.


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## gijoe (Mar 25, 2008)

Gregavi said:


> I have it wired according to the manual for "bridging" and had it wired according to the manual for 5 ch.
> Don't see how that's the problem.
> 
> 
> ...


An amp that is stable at 2 ohms stereo is only stable at 4 ohms bridged. If your speakers are less than 4 ohms, that could be your problem.


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## Gregavi (Nov 20, 2017)

gijoe said:


> An amp that is stable at 2 ohms stereo is only stable at 4 ohms bridged. If your speakers are less than 4 ohms, that could be your problem.


They're Focal Components that are 4 Ohm. Plus, that is ignoring the fact that this is happening regardless of if I have it wired bridged 3 ch or 5 ch.

Your theory would make some sense if it were only happening bridged, and if the front speakers were less than 4 ohm.


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## gijoe (Mar 25, 2008)

Considering you've already indicated that the amp gave you issues before, I'm not sure why we're still going in circles. I'm trying to offer up ideas to help, but it seems like the amp is bad. If the wiring is good, the impedance is safe, and the source signal is normal, then replace the amp, or clean the switches and pots. There are only so many potential problems, and if they've all been considered, then buy a new amp, or borrow one from a friend to test. 

You can remove the RCAs and plug in an ipod to see if the problem goes away. If the problem remains then you know it's not anything before the amp. If the problem remains then you know it's the amp, the wiring to the amp, or something after the amp. Borrow an amp from a friend, if the issues remain, it's not the amp, and since you already ruled out the source, then it's the wiring or speakers. That's really about all that can be done, it may just be broken.


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## Gregavi (Nov 20, 2017)

Yeah, I was all but convinced that the amp was broken going in. I was just hoping someone here had something that I was overlooking. I re-wired it and using the rear and sub channels only and it's working fine. Thanks for the input from everyone.


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