Vertical ripples at high refresh rate

Discussion in 'Computing and Networks' started by andry_gasy, Dec 21, 2009.

  1. andry_gasy

    Thread Starter New Member

    Dec 21, 2009
    Hi everybody,

    I have an old 17" monitor : Jean Co. Ltd, Model : JD177K3. I had the HOT blown months ago. It was a BU 4522 AX. As I could not find this same model here (Madagascar), I replaced it with a BU 2527 AX. The DC-DC converter MOSFET was also damaged. Same problem, it was a K1917 and I replaced by an IRF634.
    Now, my problem is the following:
    if I use refresh rate > 60Hz (at 1024x768), the image begins to vibrate in the left side with small vertical ripples. If I increase to say 75, it's worse and I can hear crackling (like the sound of cricket :) sorry for my english). At 85 Hz, no vibration anymore but all the characters are almost unreadable (like not really alligned vertically).
    The vertical deflection booster (TDA4866) and the HOT is also very hot (excessively?).
    Sorry if my english is not good but I really need your help. So please give some suggestions.

  2. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    I would guess that some of the electrolytic capacitors are failing.
    This is a common problem with older monitors.

    Replace all the electrolytic caps and you should see a great improvement.
  3. andry_gasy

    Thread Starter New Member

    Dec 21, 2009
    Hi Robert,

    Sorry for the late reply. Thank u for your suggestions.
    I will try it as soon as I have some money :)
    What do u think about the replacements I've made. U sure they can do the job correctly?
  4. bertus


    Apr 5, 2008