help with monitor power supply problem

Discussion in 'General Electronics Chat' started by TerraViper-5, May 15, 2013.

  1. TerraViper-5

    Thread Starter New Member

    Jul 28, 2012

    I have a monitor that didn't want to turn on twice already in half a year time. The first time I took it home (from my grandparents apartment) and when I plugged it in it started to work. I suspected it was the cable so I changed it and when I plugged it in again where it was before it was working fine. Then it didn't want to turn on again a few days ago. I immeadeately changed the cable on the spot and it didn't work either. So I brought it home again and when I plugged it in it magically worked again. Since I read that many times its the capacitor's fault for these kind of problems I opened it up, but no capacitors are visually bad. There is however a darker area around some component that looks like it has been heating a lot. I would like to ask you if you think its worth changing the capacitors anyway or if that other component might be responsible for the trouble. The monitor is over 10 years old. Thank you for your help!

  2. JayArr

    New Member

    Mar 11, 2013
    I only see six capacitors why not change them all?

    You're spending too much time trying to find which one when you already have it fixed.
  3. timescope


    Dec 14, 2011
    Take care as high voltages are present in the monitor. This fault could also be caused by a defective solder joint. Make sure all power is removed and all capacitors are discharged then check the solder side of the board. A magnifying glass would be helpful.

    Edit: I just saw your Dropbox images. CapXon capacitors : replace all of them

    Last edited: May 15, 2013
  4. #12


    Nov 30, 2010
    Be aware that your grandparents apartment might have a spotty connection in the wall outlet, especially if the building has aluminum wiring or the electricians used "stab in" slots instead of the screws to connect the wires. A device that has a start surge (like a monitor) will trigger these weak points to fail while other things will not.
  5. TerraViper-5

    Thread Starter New Member

    Jul 28, 2012
    Hmm, never thought about that. I thought that all devices would have problems if there were surges. Thanks for reminding me! I just hope that that is the actual problem.
  6. Dodgydave

    Distinguished Member

    Jun 22, 2012
    If its an LCD monitor, then the "dark burned" area is the pulse transformer for the Lcd back-light tubes. What is the number on the 20 pin IC?
  7. TerraViper-5

    Thread Starter New Member

    Jul 28, 2012
    Yes, its an LCD monitor. So its normal that that "pulse transformer" heats up like this? The number in partially covered with that paint, when I search for the lower two numbers I get nothing, for the part of the upper number that is visible I only get references to "IC" on Google, nothing specific. Here is cropped picture: