My annual breakdown has occurred with my 1980 again.

Discussion in 'Pioneer Audio' started by Hasty1, Nov 10, 2017.

  1. Hasty1

    Hasty1 Active Member

    Messages:
    101
    Location:
    Lebanon, MO
    I was having scratchy/low volume output on the left channel, but this cleared up or had intermittent issues by turning the volume knob up and down. I haven't been using this much for the last few months, so though, no big deal, clean the volume pot with deoxit and turn the knob a bunch of times.

    So, I removed the bottom cover, face, and all the screw to slide the board down through the chassis to access the volume pot. I sprayed Deoxit for faders onto the contacts and turned the knob through 40-50 full sweeps, and put everything back together. Now there is NO volume in the left channel. lol.

    Back story, this was recapped about 5 years ago, and I put a TxTurbo power supply board in this about a year ago.

    I'll be checking out some voltages over the weekend, wish me luck.
     
  2. Fhamre

    Fhamre Super Member

    Maybe other switches need attention as well. Always go for the easy stuff first. I need to say that out loud to myself on a regular basis.
    Did you desolder the pot and take it out? Did you clean the balance pot?Is your room clean?
    I'll shut up now!
     
  3. SaturationPt

    SaturationPt AK Subscriber Subscriber

    Messages:
    878
    Location:
    N.E. Indiana
    Clean, then lube. These pots do wear out and 40-50 turns isn't normal use (especially without lube).
     
  4. Hasty1

    Hasty1 Active Member

    Messages:
    101
    Location:
    Lebanon, MO
    I didn't desoler anything yet. I haven't had an opportunity to check voltages or much further.

    I'm relatively confident the issue lies in the volume control, so that means most likely it's an issue somewhere else (haha)
     
  5. mattsd

    mattsd AK Subscriber Subscriber

    Messages:
    1,608
    Location:
    Cincinnati, Ohio
    Check the volume control solder joints, they may be cracked. The 1980 volume control is supposed to be "sealed", but I've had a number of them that get scratchy. To properly clean it you must de-solder it and pull it off the board. Then remove the two long screws (be careful not to lose the small nuts!) and pull apart the gangs enough to get your Deoxit straw in there and give it a quick spray. Work it back and forth several times, then finish up by spraying some Faderlube in there and work that around as well.
     
    pustelniakr likes this.
  6. Bert 1100

    Bert 1100 Super Member

    Messages:
    1,064
    Location:
    Planquiri, Switzerland
    Low /scratchy volume that gets cured by bringing the volume up then back down sounds like oxidised speaker relay contacts.
    Was the speaker relay replaced when the recap was done ? If it is still the original relay, there is a good chance the problem is there.
     
    pustelniakr likes this.
  7. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    8,175
    Location:
    NEPA
    Be careful of which type of DeOxit is used. D5 is for switches ONLY; F5 "Fader" for pots.

    Damage to pot can result with D5.
     
  8. mattsd

    mattsd AK Subscriber Subscriber

    Messages:
    1,608
    Location:
    Cincinnati, Ohio
    I would say it was done.
     
  9. Gazdatronik

    Gazdatronik Super Member

    Messages:
    1,118
    Location:
    Chattanooga TN via Chicago
    Yes, ive messed up a few pots with D5.
    I switched to Radio Shack's TV tuner cleaner. It has a lubricant and is cheaper than deoxit, been using it for 15 years without a failure. If you can find a radio shack, anymore.
     
  10. Hasty1

    Hasty1 Active Member

    Messages:
    101
    Location:
    Lebanon, MO
    I used DeOxit Fader in an aerosol can. I took the two screws out and hit it with a short burst.

    I don't think it's a relay issue since the audio would clear up at some positions on the volume dial before. It still has clean audio in the right channel now.

    I'm assuming the volume pot is only available as used?

    I'll desolder this and properly get the fader spray and fresh solder joints and see where that gets me.
     

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