4 Replies Latest reply on Feb 5, 2011 3:44 AM by Sparkylabs

    Test clips which don't fit. (SOIC-8)

    KennyMillar

      Due to my board house fitting 50+ PIC12F629 chips onto a board before programming them, I found I had to re-program the devices in-circuit.

      This shouldn't have been to much trouble since I purposefully avoided using the ICSP pins for GPIO, since I only needed 1 bit of input and 1 bit of output.

       

      To reprogram the chips which are SOIC8 I should simply have needed to attach an SIOC test clip and wire it to my programmer.

       

      I purchased these from farnell but could not get the chips to reprogram.

       

      After a while it became obvious that the test clip was not making contact with the pins of the chip.

      Taking a closer look with an electronic microscope it was obvious there is a clear air-gap between the contacts in the test clip and the pins of the chip.

       

      I double-checked the spec of both the chip and the clip and in theory it should be a good fit.

       

      Using a fresh SOIC-8 chip which was not soldered to a board and placing it in the clip reveals that the contacts in the test clip just appear to be too-short.

       

      Unfortunately this was one of those situations where the project just had to be completed over the weekend, so I had to take drastic action and re-model the end of the test clip - so I cannot return them for credit, and there's no alternatives listed anyway.

       

      Has anyone else had any experience of piggy-backing onto SOIC devices for test or development purposes?

       

      Anyone else used these same clips and had success or failure?

       

      The link above points to :

      http://uk.farnell.com/3m/923650-08/test-clip-soic-8way/dp/178278?crosssellid=178278&crosssell=true&in_merch=true&

       

      -Kenny