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Lee Adamson

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About Lee Adamson

  • Birthday 08/07/1978

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    Antique Computers. Antique Guns.

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  1. Lee Adamson

    Apple IIgs ROM 03 system bad error

    I think those Zilog rs422 chips were used in a lot of other machines. You ought not have tremendous trouble finding donors, I wouldn't think? I have a ROM3 board that took a Maxcell Bomb to the face that I've been trying to fix, even though it is pretty hopeless (seriously man, it is *bad*, really capital-B *Baaaad*), just to see if I can. If/when I get frustrated and give up, I'd be willing to trade that board to you for something interesting/useful, if you want it. It would be easier to get the chips off with a hot air station, but if this donor board ends up being junk anyway then I guess it doesn't really matter if you pull up a bunch of pads trying to get them off, as long as none of the pins break. Alternately, I could probably desolder the serial chips and send them to you, if/when I give up on trying to fix the board, although it makes me sad to scrap such things myself......... Likewise, if you want to get rid of one (or both) of your malfunctioning boards, maybe I could put myself together one working board to put in my spare case. I'm more of a trader than a cash buyer, though......
  2. Lee Adamson

    IIgs keyboard not working at all!

    (Disclaimer: I'm just a hobbyist and I don't really know what I am doing half the time.) If you have the appropriate test equipment, I'd start by checking to be sure that there isn't a short to ground on the power rails. Certain types of capacitors can form a short circuit when they fail (old tantalums in particular). I can't tell what those blue ones on your board are (metalized film?), but if you find a short on the power rails, then I'd start with them. That being said, I've found that the IIs of the era seem to have used far better capacitors than the same-era Macs. I've never had to recap a II, but old Macs are another story........ Failing that, I'd see if I could find a pinout for that controller IC and start poking around with an oscilloscope. If that's what's bad, I think there's probably a pretty good chance that you could desolder a replacement from an appropriate Mac board of the same era to replace it (edit: assuming there isn't some special magic going on with that particular chip to make it an italian layout keyboard).
  3. Lee Adamson

    Apple IIGS Repair Help

    I'm sending him my spare ROM1 mobo and a RAM card, and he's sending me his dead one to try to fix. It'll be an interesting project. It looks pretty dire to me, lol, so I'm not gonna hold my breath. Gunna have bodge wires stacked so deep underneath that it won't snap back over the tabs. :3
  4. Lee Adamson

    Macintosh LC III recap - Capacitor Recommendations?

    When I did my IIci, I was out of SMD electrolytics of the correct values, so I just cut the leads on through-hole electrolytics really short and soldered them to the pads. It actually worked far better than I expected, and I think I'm going to just leave it that way until they start failing (I used cheapo chinese caps, since I expected it to just be a temporary experiment and wanted to use them up). I generally prefer Panasonic, and that's what I'll probably use next time, being afraid that I'll just have the same trouble in another 30 years if I use the "correct" SMD electrolytics, but any quality brand Japanese, American, or European capacitors ought to last just fine (and that should apply to SMD capacitors, too). One thing that I *am* suspicious of is when people replace SMD electrolytics with tantalums. When electrolytics fail, they fail open, and the circuit is (hopefully) designed with that in mind. When tantalums fail, they fail *closed*, and again the circuit is (hopefully) designed with that in mind. But with the recent popularity of recapping with tantalums "because they don't leak", I think we're going to see the magic smoke coming out of a lot of boxen 30 years from now when those tantalums start failing. Best case it'll keep PSUs from powering up, but worst case it might burn traces on motherboards, which would be really unfortunate.