smr-4 power suply test fail 5.64V -4.94V 0.1V
  • mcpepemcpepe
    I am in Step 4 of the SMR-4 assembling. The test is OK but all the blue points are at 0.01V, all the red points at 5.64V, and all the green points at -4.94V.
    I am using a 9V power suply.

    It is OK to have 5.64V? Can I continue soldering?
  • pichenettespichenettes

    No, you’re going to damage the MCU if you do that! It looks like the 7805 is not operating properly. What is the voltage you get straight out of the power supply?

  • mcpepemcpepe
    12.12V
  • pichenettespichenettes

    Supply voltage is high enough, OK.

    It looks like the 7805 is damaged. I found in the forum that someone had the same problem and solved it by replacing the 7805.

  • mcpepemcpepe
    OK. I'll try to find a 7805 in a store here!. (I live in a little town of Spain).
    Thanks for the help.
  • mcpepemcpepe
    I just got this from a friend.

    http://dl.dropbox.com/u/8640960/CIMG3715.JPG

    L78S05CV
    SGS 6438P

    Do you think it would be compatible?
    I can just try it and see...
  • pichenettespichenettes

    Looks good.

  • mcpepemcpepe
    I put the new 7805 and now it works ok. -4.93V 4.99V 0.01V.
    Thanks for the help!
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