Macintosh Classic CRT problem

Discussion in 'Apple Collectors' started by macintoshmartin, Dec 23, 2010.

  1. macintoshmartin macrumors newbie

    macintoshmartin

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    #1
    Ok, today I tried to turn on my Classic but when I turn it on, i can hear the fan spinning and like it is running, but nothing shows on the display and I hear a crackling coming from the CRT. Does anyone know what is wrong?
     
  2. gkarris macrumors 604

    gkarris

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    Dec 31, 2004
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    #2
    Caps or CRT's out... be careful if you crack it open...
     
  3. macintoshmartin, Dec 23, 2010
    Last edited: Dec 23, 2010

    macintoshmartin thread starter macrumors newbie

    macintoshmartin

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    #3
    I just carefully disassembled the Classic carefully, and when I took off the board on top of the CRT, it looks like a round glass piece came out, I think that is the problem

    I think it's called the yoke assembly
     
  4. gkarris macrumors 604

    gkarris

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  5. MacTech68 macrumors 68000

    MacTech68

    Joined:
    Mar 16, 2008
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    Australia, Perth
    #5
    Actually, it sounds like the nipple of the CRT (Cathode Ray Tube) has snapped off. If the piece of glass is cylindrical and about 4mm diameter, then that's probably what's happened. Time to buy another Classic (for a spare tube at least).

    Take a look at this page:

    http://www.kevinomura.com/macs/classicII/index.html

    Yes, some images are missing :rolleyes:

    The third image down shows the tiny glass nipple in the middle of the CRT "neck" pins. Behind the gold colored rings is the "yoke".

    I've seen these get snapped of in transit, or if the crt neck board (the small rectangular circuit board that plugs onto the back) is accidently knocked. Yes, I've done it myself and I think most techs have. The 9" CRT nipple is quite a delicate beast.
     
  6. macintoshmartin thread starter macrumors newbie

    macintoshmartin

    Joined:
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    #6
    Thank you all for your help. Unfortunately, it was the CRT "nipple" and I guess I need to replace the CRT. I might just sell it for parts, everything else was working fine.
     

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