Indeed.  Here's the service manual and schematic for his HK.  Skip to page 24 to see the layout of the output stage.

I'm not picking on deoxIT at all - just reverting to basic troubleshooting technique.  Namely, find the source of the problem and then determine the best repair solution. 

If its the tape monitor switch, cycling that viscously a few times should bring back some of the signal, if even staticy/distorted.  If no action there, it could the the input selector switch(s).  Not all switches are suitable for use with deoxIt and similar - as they may be sealed against contamination.  In that case, the only solution is replacement, or if you are ever so brave - removal for total disassembly, clean and reassembly.  Of course this all assumes its oxidation that is the cause of the woe - which is indeed often the case.  Could just as easily be a cold solder joint on one of the switches, interrupting the signal for that channel - also a very common issue in amps where the pads for the low level signal switches are soldered directly to the board.

Could also be a minor failure in the preamp circuit.  The fact that the unit still has power and apparently hasn't popped any fuses may indicate a problem somewhere in the preamp area, and not anywhere near the outputs.

As I said, I'm not familiar with deoxIT as its been a while since I've done any work requiring such a product.  I'd be leery of any high-priced solution that removes oxidation.  Its not like this is a new issue at all - back when I was servicing systems, one of the best products I found was these small green aerosol cans from Sony called ... wait for it ... "Sony Lube".     Can't recall where we got it at the time, but I liked it much better than other lubes we used - it had a low residual and was silicon based, IIRC.  As you likely know, there is never one spray, lube or protectant that does it all in every circumstance.  My shop bench is a testament to that, as is any decent electronic bench - with at least five different spray cans awaiting the next victim/patient.

And yeah, audiokarma is a good place for info.  As always, read, digest and read some more before applying any miracle fixes that anyone is touting.  That said, there's still plenty of good info on vintage audio repair to be found on Usenet / Google Groups.

How many years did you spend as a tech doing electronics servicing for consumer electronics?  "Large-ish" "output capacitors"??  Say what??

Sounds to these ears like you are applying the tiny bit of knowledge you may have acquired in fixing a computer motherboard with "bad caps".

Thanks mzpro, this one "looks" good, and the price is right...


  

Before applying any fixes, fluids, let alone a soldering iron, it is necessary to diagnose the specific area of failure.  Oxidized tape monitor switches are indeed a common failure - proving they are the cause is straightforward.  Methods for fixing the tape monitor switch are not always reliable, and are dependent upon construction of the switch - unless the part is replaced with a new switch from the oem.

As for "chinese fakes", I suppose you mean subs from NTE and the like - for the 2Nxxxx devices...

If you are looking for a decent 2 channel receiver try this
Sony 2 channel Receiver - $160

Amazon has it for $123

Man, I use that line all the time!

But seriously, it's not as bad as it sounds. And it's already busted, right? Can't break it any worse by messing with it. Heck, if I was close enough I'd take a look at it myself.

I have several 70's-vintage Sansui receivers that are still going strong. The one my Dad bought in 1970 is still solid after many years of abuse, and it'll kick the doors off a lot of new gear. The old transistor gear is pretty rugged, and fixable. The new chip-based amps are far more difficult, if not impossible, to repair.

you can fix it....

.
Oops. Your right should be one "c" and two "m" 's.... Dang, I really was an English major.

I'm a really bad speller, but that Recommended word looks all wrong. 

See, I use THAT line all the time!

 And it's already busted, right? Can't break it any worse by messing with it.

Reminds me of the old Steve Martin routine about how to make a million dollars and never pay taxes!

"First, make a million dollars...." 

 

 Which will require removing the circuit board, de-soldering the old cap(s), and installing new ones. 

Yay, my trusy Harmon Kardon HK380i tuner/receiver/amplifier circa 1979 just lost it's right channel. I was using it in my living room streaming to an Apple Airport Express, so RP is currently playing though one speaker. Got a good 30 years out of that sucker!

Now I get to go audio shopping. Oh yeah. Wait a minute, I'm broke! Well not totally, can anybody reccomend an inexpensive powered speaker system. I've been kind of looking around lately and so much is surround sound stuff that I'm just not into. I just want something in the 1 to 2 hundred dollar range that will do the job. I'm using a pair of Edirol powered speakers in my bedroom that sound great, but I'm not sure I wan't two pair of those, besides those are more studio monitors (near field) than I would like for the living room.

Anybody using anything that they love?