Loading ...
Sorry, an error occurred while loading the content.
 

Re: Crow Bar circuits

Expand Messages
  • joshbensadon
    ... Ouch, that must have been very frustrating! The guys down at the store must be thinking You again? . Well, this would be one of those things in 20 years
    Message 1 of 10 , Sep 7, 2012
      --- In midatlanticretro@yahoogroups.com, "Bill Sudbrink" <wh.sudbrink@...> wrote:
      >
      > LCD display also survived. The "repair" ended up taking almost an entire
      > frustrating weekend. It was my wife's computer. Initial evaluation:

      Ouch, that must have been very frustrating! The guys down at the store must be thinking "You again?". Well, this would be one of those things in 20 years you can look back at and laugh (if you're not laughing, add another 20 years).

      > (Oh, I guess the speaker survived too)

      Oh, that's good, that saved you $0.50 for a new speaker. (Sarcasm never comes through in email)
      I guess that was a weekend of "what can go wrong next?". I've had my share of bad repairs, but not that bad. Well, chaulk it up to experience.

      Cheers,
      Josh
    • joshbensadon
      ... Are you saying the transistors in the old analog computers are robust? I haven t looked at part numbers yet, but they look like the old germanium TO-05
      Message 2 of 10 , Sep 7, 2012
        --- In midatlanticretro@yahoogroups.com, David Gesswein <djg@...> wrote:
        >
        > You can look up a couple of the part #'s to see the breakdown voltage.
        > Since the analog computers weren't normally trying to use the fastest
        > transistors they may have a good margin on breakdown voltage.
        >

        Are you saying the transistors in the old analog computers are robust? I haven't looked at part numbers yet, but they look like the old germanium TO-05 case style. I have zero experience in Analog computers, I would love to pick someone's brains on them. New thread?

        Cheers,
        Josh
      • s100doctor
        Bill described what appears to be a catastrophic failure of a 21st century personal computer s power supply, that apparently took all the other components with
        Message 3 of 10 , Sep 8, 2012
          Bill described what appears to be a catastrophic failure of a 21st century personal computer's power supply, that apparently took all the other components with it, drives and video cards and of course the "motherboard".

          David Gesswein addressed some issues of analog computers which used discrete transistors (as opposed to vacuum tubes, for example).

          But the original question was about crow-bar circuits on power supplies, or tantalum capacitor failures.

          My point in calling this sequence out, is that I caution against trying to draw broad conclusions from very specific kinds of repair problems, component failures, and types of design - conclusions across different eras of personal computers. I think broad conclusions and comparisons are not productive. and even harmful.

          Without posting a lecture about it......I think it's more reasonable to focus a discussion of computer repairs, to a fairly specific class of computers - specific time and place, models, designs - than to go off to talk about a five-year old computer failure in the same thread as 40-year-old transistors in an analog computer. It's like talking about an engine breakdown from an oil leak in a 2009 Toyota Camery, in the same discussion as a head gasket leak in a Model T Ford engine. Those are good discussions, but not the SAME discussion, in my informed opinion; what you learn from one won't help much with the other.

          Herb Johnson
          retrotechnology.com
        Your message has been successfully submitted and would be delivered to recipients shortly.