trouble with trouble shooting??

Discussion in 'Homework Help' started by Bigcountry, Oct 25, 2008.

  1. Bigcountry

    Thread Starter Active Member

    Jul 4, 2008
    I am really having trouble with this problem attached. I don't know if I am over looking something simple or not. It could be I am just tired from working all night. hopefully someone could get me pointed in the right direction.

    thanks for any insight.

    I would Check C4 for high leakage current.
  2. studiot

    AAC Fanatic!

    Nov 9, 2007
    When doing these it is a better exercise if you work through each option and know why you have discounted it.

    A Some of the supplies are pretty close to nominal. this would not be the case with shorted rect diodes.

    B R1 open would produce zero output at F

    C This leg of the output is likely to be at lower current but voltage is not as low proportionately as the third leg.

    D All the highly disturbed outputs are fed from C4

    E C9 going open would only affect rail D, not the others

    F Shorts on any of these capacitors would lead to zero output

    G The psu worked once so changed values are always possible, but not wrong ones.

    There I haven't (quite) done it for you.
  3. RiJoRI

    Well-Known Member

    Aug 15, 2007
    Another thing that might help is to write in the erroneous voltages next to the correct ones. Doing that makes the probable answer pop out at you.

    Check out The Universal Troubleshooting Process at, especially their 10-step process. (No, you do NOT begin with "I am a recovering troubleshooter"! :D )

  4. Bigcountry

    Thread Starter Active Member

    Jul 4, 2008
    Thanks for the help. that helps a lot. So I think I was right with C4. right? that helps with writing the erroneous voltages on there too. It is hard to work a full time job and go to college. I don't have much confidence since I am kind of just starting with electronics. lets hope I can become a Xpert in 10 step process. :)
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    Life gets very different when you are the person on the spot with a critical problem to fix located many miles from the support facility. You can never know too much about the equipment or electronics.