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Thread: Video: Why I Don't Include Sockets for Every IC in Kits

  1. #1
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    Default Video: Why I Don't Include Sockets for Every IC in Kits

    I've been working on the first prototype run PC board for a new Altair 680 RAM board. It has a lot of prototype area, and some test points that make it easier to add custom circuitry to the board. Yesterday, I built a simple 8-bit LED lamp register onto the board to test some of the circuitry for user-built features. It didn't work! I hooked up the logic analyzer and...then it did work! See video below for the explanation:



    Yes, likely a bad socket -- I don't know for sure because I haven't powered the Altair 680 off to verify. And, this isn't some junky single-wipe socket pulled off an old board from the 70s, this is a nice Augat machine pin socket. New, or at least NOS, with gold plated inserts and everything. And yet, when you remove the DIP clip, the board stops working.

    This is one of the reasons I don't provide sockets for every IC on a board, and why I discourage other hobbyists from using sockets everywhere. I like OSI's advice in their old manuals: unless the chip costs a lot more than the socket, don't use a socket.

  2. #2
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    Could also be the IC packaging--have you tried another IC in the socket?

    I can't say that I've ever seen an Augat machine-pin socket fail in 40 years. Commercial wire-wrap prototyping boards have thousands of the machine-pin socket pins. One reason they're used is because of utter reliability.

  3. #3
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    My mistake, this is apparently a Garry socket. Still not junk!

    I swapped ICs with no change. Soldered the new, known-good 74L00 into the socket and problem solved.

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    I'd be interested in a post-mortem of the socket. It might shed light on why one brand may be better than another.

  5. #5
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    Quote Originally Posted by Chuck(G) View Post
    I'd be interested in a post-mortem of the socket. It might shed light on why one brand may be better than another.
    That might be a little difficult, being as how it's full of solder now!

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