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Onkyo A-7090 Amp problem

ebprod

ebprod

Active Member
I have a borrowed Onkyo A7090 Amp. The amp hadn't been used in years. I am only getting sound from one channel, unless I press the Loudness button.

I've tried Deoxit, and I can get both channels to come back but it only lasts a few days.

Is this amp any good? Is it worth putting any money into fixing it?

Thanks.

-Joel
 
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It likely needs to have EVERY switch cleaned and worked several times. This not uncommon with old gear.
I would clean it, align it and enjoy. That is a nice amp.
 
They are nice amps, but the switches are notorious for being troublesome.

Also, be careful with the front panel lettering. If you look at it wrong it will come off, say nothing of getting chemicals or cleaners on it.
 
My Onkyo A-7070 had similar issues. Like others said, clean all the switches you can, work them in and out several times even if you can't get to them with Deoxit. It will come around. That line of Onkyo was highly rated in it's day, good stuff.
 
Agreed. I had one of those onkyo integrateds from that period, and it was a solid performer, with a really good phono stage. It's worth the effort.
 
I've gone in a cleaned everything I can find several times now. The problem is still the Loudness button. With the button off, the right channel is completely dead. When I depress the channel is comes on.

Any other suggestions, other than keep at it with the deoxit?

-Joel

-----------------------------

Just gave it another try- and the amp is working perfectly!! This has happened before, and then a few days later the channel goes out again. Maybe I've cleaned it enough this time.

-Joel
 
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I have a 7090 and virtually every switch on it has caused it to cut out at one time or another. Deoxit and fader lube every couple years seems to keep it running smoothly.
 
De-Oxit isn't really a very strong cleaner. There are some controls it just won't clean. Try a good non - residue contact cleaner like this:
http://www.mcmelectronics.com/product/20-2005

Inject it into any opening in the switch body you can find, then work the switch back and forth at least 30 times. Allow it to dry, then follow with De-Oxit as a preservative, working the switch again. I find this method to work well most of the time. It takes some ingenuity to find an opening to squirt the cleaner into. Some push switches have a phenolic bottom with a couple of small holes in it. Sometimes there is a hole in the metal body. Sometimes you have to inject it into the area where the spring is. You may have to remove the front panel and remove the board the switch is on to get to it. Just squirting cleaner in past the buttons isn't going to work.
 
Well, it worked fine until I put the cover back on. Now it is back to the original symptoms.

I get the feeling I am not getting inside the switch with the cleaner. It looks like an enclosed plastic box. I've attached pictures of what I am dealing with.

-Joel
 

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You're going to have to pull that board out. Those push switches are a pain to clean in situ.
This is what you're dealing with:
attachment.php

You can still try working that switch until is capitulates~
 
Another option instead of disassembly... I've used very small drill bits on pots before so I could spray inside them. YMMV on those switches, but once you have an opening blast away!
 
You don't have to do any of that. Remove the front panel and inject the cleaner into the switch where the push rod goes into the body of the switch.
 
I took the front off, sprayed past the spring, and the channel came back as before. However, for the second time in a row the channel dropped out as soon as I put the cover back on. This time there is faint sound coming out of the right channel. If I press the Loudness button both channels come on strong.

Could there be something else going on beside a dirty button?

-Joel
 
ebprod said:
I took the front off, sprayed past the spring, and the channel came back as before. However, for the second time in a row the channel dropped out as soon as I put the cover back on. This time there is faint sound coming out of the right channel. If I press the Loudness button both channels come on strong.

Could there be something else going on beside a dirty button?

-Joel
Click to expand...

Are you still using De-Oxit only?
 
I'm still using deoxit, but now I've run out. You mentioned a heavier duty cleaner, is there something I could buy locally at Radio Shack that would work?

Also, I was moving my RCA's from my CD player to see if the symptoms would change. I moved it around several times without any change. Then the last time I put it on one of the tape inputs and both channels came back. Now all the inputs are working again as normal. I did this without messing with any of the front buttons.

I'll try it again later today and see if it is still good. I've gotten it working before, it just doesn't last.

-Joel



dr*audio said:
Are you still using De-Oxit only?
Click to expand...
 
Nothing at Radio Shack, but you can get CRC Contact Cleaner at an Auto Part Store. Should be ok.
 
I wonder if there isn't also a bad solder joint where the switch is connected either to the pcb or wiring? Putting a cover on and off isn't going to affect the switch internally so there must also be some other stuff going on.
 
If this continues, pull the cover off without doing anything else and see if it works. If so, look for bad solder joints or a pinched wire, shorting to the chassis. Or a crack in the board. Also check the soldering on the input jacks on the back. Look at the leads for the jacks and the pads they are soldered to. Look for a dark ring around the leads. If you see that, re -solder the leads.
 
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