Macintosh 512k / 128K issues

Discussion in 'Apple Collectors' started by Ih8reno, Nov 27, 2015.

  1. Ih8reno macrumors 65816


    Aug 10, 2012
    Hi everyone

    I currently own a 128K which seems to have an aftermarket upgrade to become a 512K and may be buying a 512K. I have a couple of questions and was hoping you could answer them for me.

    1. the upgraded 512K makes a constant beep when booted, non stop. Is there anything I can do to stop it or could you tell me what the issue may be?

    2. A second original 512K which I may be getting according to the seller boots to a black screen, claiming it needs a battery to boot properly. I tried my upgraded 128K and it doesn't seem to need a battery. Is the issue more then likely something that I'd need to repair?

  2. bunnspecial macrumors 603


    May 3, 2014
    No advice on the first, but does the second beep when powering on?

    If so, ask the seller if laying the computer on its side or smacking the side(left side when facing the screen) will give any signs of life on the screen. If it does, the culprit is likely fractured solder joints on the analog board. This is a quick and easy fix(I've had to do it on both my 512Kes)-you just need to reflow the joints with a little bit of fresh solder.
  3. Ih8reno thread starter macrumors 65816


    Aug 10, 2012
    Its a constant beep never stops...
  4. MacTech68 macrumors 68020


    Mar 16, 2008
    Australia, Perth
    1. If you get a grey screen with floppy disk icon, the possibilities are a bad Horizontal Width coil, or a failed flyback. There's other possibilities - do you have a recording of the sound?

    2. The machine doesn't need a battery to turn on and boot-strap to a grey screen with floppy icon. There's one or two very simple fixes, OR there are a lot of other possibilities. Does thumping the cabinet do anything?

    Can you get any further descriptions of any sounds, squeals, hum, hissing? Has the seller tried lightly thumping the case? Can you get video (preferred) or audio of the two machines powering on? Has the seller tried the brightness control on the front panel?

    It's very difficult to definitively say what faults you may be facing with such scant information from the seller. I realize there is/will be a limit to what you can get the seller to do, and the quality of their descriptions of the exact symptoms (years of experience of customer's descriptions of symptoms tells me that).

    Customer: "It won't turn on"
    ME: "Do you hear any sounds?"
    C: "yes"
    ME: "Does the green light on the screen come on?"
    C: "yes"
    Me: "Do you see anything on the screen"
    C: "No"
    Me: "Not even a grey pattern on the screen"
    C: "yes, I see a grey pattern but it won't turn on"
    Me: "please hold" - *bangs head on desk*

    To answer you last question, both sound like something needs repair.

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