Question regarding testing voltages

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  • sam67
    Badcaps Veteran
    • Dec 2009
    • 256

    #1

    Question regarding testing voltages

    Hi i have a question regarding testing for voltages on a LCD monitor..

    The pic i have just enclosed is one of my proview monitor that had bad caps which i have successfully recapped.. As you can see from the pic it has the power board and main board attached to the chassis.

    Now this monitor is working fine ,but just say for an example that this monitor was not switching on and i wanted to test at the bridge rectifier that there were the correct voltages at the 2 AC pins of rectifier and then check the main filter capacitor for the correct DC voltages.


    Now as you can see from my pic that the power board and main board are joined with a connector and that a ribbon type cable from the main board goes to the Lcd screen as do the ccfl connectors from power board.

    Now the ribbon cable is small and there is not much room to get at the main board or power board when this cable is connected to the LCD screen.

    Is it ok to remove this cable from the LCD screen side and then just leave everything else connected and test the voltages from the silk screen side of power board ( what i am saying is will removing the ribbon cable cause any issues to the voltage testing).

    Also say i wanted to do more testing on the power board but on the component side is it ok to remove both the main board and power board from the chassis and place them say on a none static surface to test more voltages ,again will this have any affect on the voltage readings when not connected to the chassis ( i.e grounding)

    Obviously it would be better if the power board was facing up with components showing for better testing in some cases.

    What do you guys do when needing to test a monitor for the correct voltages and you need more room to test and get at the right connectors to do your testing ..

    Hope i have not confused anyone with my wording lol.

    Like i say i am a newbie but wanting to get a better understanding when testing.

    I have recently been buying tools to help me along as well as some ebooks on SMPS and monitor trouble shooting but none really explain how to layout the pcbs when ready for testing .

    Hope i can get a better understanding as i am really eager to learn and this place is the best for the correct advice .












    Last edited by sam67; 02-15-2010, 07:46 PM.
  • sam67
    Badcaps Veteran
    • Dec 2009
    • 256

    #2
    Re: Question regarding testing voltages

    I guess what i am saying is can i remove both power/main board from chassis and board from LCD screen and hook them together and power them like a sort of bench test for easier voltage testing so i have more room to test.

    Comment

    • cadiman
      Badcaps Veteran
      • Mar 2010
      • 397

      #3
      Re: Question regarding testing voltages

      I think there are better qualified people here to answer this question than I, but you may need to post this in tv/video to get a reply. I have worked on some stuff where you really can`t get to parts of the board to check volts. I have set boards up on an insulated table (cardboard). You have to be creative when troubleshooting sometimes.

      If you have schematics you can find the test points in better places on the board your working on. If you have a working unit start logging info where you can get to it. In electronics (auto and other equipment) we call this easy pickins method. test the stuff you can reach without taking the whole thing apart. I would log all voltages from the power supply first. Good luck!
      Cadiman

      Comment

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