Beseler 8177 timer repair

Discussion in 'Darkroom Equipment' started by gleaf, Jul 21, 2013.

  1. gleaf

    gleaf Subscriber

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    Looking for a schematic for the Beseler audible repeating time.
    The workhorse is ill and needs a fix.:blink:
     
  2. ChuckP

    ChuckP Subscriber

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    I'd like to also have one. What's your problem? I did find out that this is basically an analog timer. It switches different RC values in to set the time. I sprayed down the switches with contact cleaner and it seemed to help the unreliable times. Been awhile but I believe it was just using a 555 type timer for the timing source.
     
  3. bsinmich

    bsinmich Member

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    Are you sure about the number? Mine is 8711. There is one for sale on the Hollandcraigslist for $10. The guy doesn't know what it is and has had it relisted for months. l
     
  4. gleaf

    gleaf Subscriber

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    Was hoping I wasn't going to have to do my own schematic. Never cost effective to do what has already been done.
    Yes to nameplate ID is "Catalog Number 8177" Front Panel labeling is a bit different than the current
    offering. Name and logo on upper left corner rather than right.
    Timing circuits are likely the 556 and a 555 on the board, for tenths, seconds, and beep.
    Haven't hunted down the what goes where yet,
    Assume the switches go to the resistor networks. Trimming resistors evident..
    Will be checking the coil for drive on the relay. Get and idea if we have dead relay or something more electronic.
    Beseler offered that a repair is likely more expensive than buying a new one if I sent it in. "No schematic available" from them.
    No problemo, image both sides of the board, ohm out the traces and check out the wire harness.
    I should have layout, schematic and parts list developed in a few days.
    Gralab will handle it until I have the 8177 repaired.
    Thanks to all. Grey Head needs a reality check often at my age.
     
  5. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    I have a working one you can have for a song plus shipping. Knobs are a little stiff though.
     
  6. gleaf

    gleaf Subscriber

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    The answer was on half of the 556 dual timer chip was inop.
    All is now well with the beastie.