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Peavey Special 212 Transtube - No sound until you crank it, then it's fine until next cold powerup

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  • Peavey Special 212 Transtube - No sound until you crank it, then it's fine until next cold powerup

    I have a peavey special 212.

    When you turn it on, there's no sound. If you turn the volume way up and thrash around on the guitar after about 30 seconds it will BLAST on, then it behaves completely normally after that.

    Other info:
    Same behavior when using the low gain or high gain input.
    Same behavior in the Clean or Ultra (distorted) channel.
    Sometimes there is faint sound prior to 'blast off' (blast on, technically :-)

    I took the board out and looked for solder joint problems. Nothing obvious. I re-flowed the input jack connections.

    One of the output transistors looks kinda crusty. It has some internal resistance, and was the same as the others nearby (though I forget what the # was).

    Suggestions on how to zero in on the issue? It seems like a bad solder joint on the output side somewhere... right?

    Schematic: http://schems.com/bmampscom/peavey/P..._schematic.pdf

    -Chris
    Last edited by 4n6Days; 09-12-2019, 05:39 PM. Reason: added schematic link

  • #2
    FX return jack or "power amp in" jack always a suspect.

    Read all about it in our handy sticky. And keep it in mind for ANY similar symptoms, in any amp or mixer, it's often the culprit.

    https://music-electronics-forum.com/...ad.php?t=28549
    This isn't the future I signed up for.

    Comment


    • #3
      I cleaned the bypass pins on the Power Amp In and FX Return jacks and sprayed them with Deoxit.

      Preliminary test: I think that was the issue!

      Thank you!!

      Comment


      • #4
        Originally posted by 4n6Days View Post
        I cleaned the bypass pins on the Power Amp In and FX Return jacks and sprayed them with Deoxit.

        Preliminary test: I think that was the issue!

        Thank you!!
        Kool! You may want to follow up after the deoxit spray, with a shot of non-residue cleaner. Deoxit, good as it is, leaves an oily residue that eventually gums up, can cause corrosion too. All it takes to make it work is a few molecules - it's never a case of "more is better" with that stuff. (Same goes for the other Caig "miracle" chemicals.) I use it on tube pins & sockets as well, same cautions apply.

        It pays to exercise those jacks you cleaned too. With the amp off, just jam a plug in there a dozen times or so. Do that a couple times a year, that should be plenty. Storing the amp in clean dry conditions is also a big plus. Damp cold air in garages, basements, sheds, barns brings on corrosion without a doubt. Same goes for gear left in vehicles. Might as well be out in the weather.

        If you read a lot of threads on here, often - but not always - it boils down to simple stuff. We're reminded by some top techs, a phrase that's also heard in medical schools, "when you hear hoofbeats think horses, not zebras." Also, rust never sleeps. Corrosion is our constant enemy.

        Hope that keeps your Peavey going for a long long time. And welcome aboard!
        This isn't the future I signed up for.

        Comment

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