Certain Columns Do Not Work On A Newly Built 256

  • I just assembled it all tonight, and for some reason certain columns aren't jiving.

    check out the picture:


    i just used a multimeter and the diodes still have similar voltage across them as diodes from working buttons. but perhaps this doesn't prove anything?

    Really looking to get this solved asap, seeing how i have a performance on sunday.


  • and that's just a blown LED all the way in the right column

  • also,

    it worked perfectly before putting it into the enclosure.

    I wonder if it's the logic board, because when i got back today to finish building this, the logic board was on the concrete floor of my basement, so maybe it dropped and was damaged. i hope not.

  • reheat your connectors. this is a very common problem-- cold solder joints.

  • So i narrowed it down a little to being driver/keypad error. I switched the upper left and lower right connector (1 and 4) and still got the same light setup, although now the test saw that the first key was able to be pressed (and in conjunction it lit up the 1st key of the lower right pad).

    So i reheated and added tony dabs of solder to all the components on the driver of the upper left keypad, plus the surface mount connectors on the actual keypad, and i'm still getting no response from the first column.

    if one diode is out, does it affect the whole column?