HP L1906 fixing (pictures and steps)

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • diodine
    Member
    • Dec 2011
    • 46
    • Spain

    #1

    HP L1906 fixing (pictures and steps)

    An old non working HP L1906 monitor was given to me two or three months ago, as crap to be dumped. I have searched the forum and I have found there are at least three versions of this same electronics and no reference to the steps to open the box.

    So now I am writting this post to help others. Firstable I want to copy here the opening steps, as written in an hp forum by an angry user. In no way I am subscribing necessarily his(or her) expressions about hp, the monitor, etc , but I won't change a word because it is his/her work :

    "L1906 Monitor - No Power FIX IT YOURSELF or Pay HP $$$ YOU DECIDE
    Options

    ?05-21-2009 12:03 AM

    Lucky you - You bought an L1906 Monitor from HP and one day all of a sudden, the Green Power LED just didn't turn on anymore. The Monitor appears to be dead!

    Why?

    Well I suspect it is because HP decided to save a few pennies by buying "second tier" electrolytic capacitors. You can read all about them on wikipedia, just look for "capacitor plague". In your monitor, several of them have burst, or are about to, and they have vomited the contents of their stomachs onto the PCB of your power converter. Mmmmm - yummy.


    Not to worry. (A) For a "nominal" fee, the good folks at HP will gladly swap your monitor out for a replacement unit( with a few minor scratches).

    Or (B) you can follow these handy steps to fix it yourself, while flipping HP a collective "bird", now and forevermore.

    Personally, I went with option B.

    Option B:

    1) Face HP world headquarters and extend the middle finger of your right hand in salute, while uttering the words "BITE ME!" with menacing conviction.
    2) Remove the power from your monitor and allow it to sit overnight so that all capacitors can discharge, thus making it safe to work on.

    WEAR SAFETY GLASSES FOR THESE NEXT STEPS

    3) Insert a very small flat bladed screwdriver in the gap between the silver front bezel and the black plastic back (do this at the bottom of the monitor so if you scratch the bezel it will be less noticeable.)
    4) Gently push the black plastic inwards which will deflect the black plastic retaining tabs inwards, and will release the silver bezel.
    5) Once you have the bottom off, work up the sides and release the top. Then remove the bezel completely. Then unscrew the ON/OFF + Menu Button panel and move it aside being careful not damage the wires that attach it to the unit
    6) Place the monitor face down on a towel (or other soft surface, for example a scantily clad super-model will also work)
    7) Gently compress the top cap of the tilt stand to disengage the locking tabs that hold it on, and remove it revealing the "third screw" of the tilt mount. (I had to use a lot of 4-letter words to find this, your mileage should be considerably superior)
    8) Unscrew the three screws holding the tilt stand to the monitor back and remove the tilt stand. These screws have loctite, so use a good screwdriver and press hard. If using a super-model, she should be squealing with each torque thrust.
    9) Remove all 8 screws on the rear panel - 4 One in each corner, and four more on each corner of the raised section in the center of the monitor.
    10) Remove the back cover
    11) Remove the two screws on either side of the AC power receptacle and the 4 wires that plug into the monitor chassis, noting the order in which they are connected.
    12) Remove the 4 screws that hold the LCD panel to the chassis
    13) Gently remove the panel enough to get access to the power board, being careful not to damage any wires or their connection points.
    14) Remove the 4 power board mounting screws, note that one is different, and remove the power board.
    15) Remove all defective electrolytics (especially 5V 1000uF near the +5V outputs). The defective ones are bulged or have burst.
    16) Mutter expletives under you breath. If young children are present, alternate "Darn!" and "Fudge!"
    17) Clean off the HCl residue left by the burst electrolytic using board wash or 99% ISOPROPYL.
    18) Replace the defective electrolytic capacitors. In fact, just replace all of them, that way this will be your final repair on this POS.
    19) Suppress your anger.
    20) Re-assemble and test.

    Please post your repair experience on this thread. If you have any sentiments that you would like to express to HP, please use this forum as a place to indulge in an immersive catharsis. Feel free to vent from the orifice of your preference.

    The capacitors did.

    http://www.fixya.com/support/t558081-monitor_will_not_power"
    Mine had exactly 3 caps numbered C822, C823 and C824, 1000 uF 10 V CapXon, vented off and not working. The monitor didn't power on. The fixing consisted in desoldering of the old three and soldering of three new Daewoo same specs but 16V. The monitor started at first try and has worked several hours with no problems.

    Here are the pictures, I expect them to be useful.

    I also am attaching the service manual I have found, although it does not seem to address the problem this monitor had (or at least not in the way I made).
    Attached Files
    Last edited by diodine; 01-11-2015, 07:05 PM.
  • budm
    Badcaps Legend
    • Feb 2010
    • 40746
    • USA

    #2
    Re: HP L1906 fixing (pictures and steps)

    Please make sure to use LOW ESR type caps not general purpose type otherwise it may last weeks or months since the power supply is running 24/7 even when you turn off the monitor.
    http://s807.photobucket.com/user/bud...in=true&page=1
    Never stop learning
    Basic LCD TV and Monitor troubleshooting guides.
    http://www.badcaps.net/forum/showthr...956#post305956

    Voltage Regulator (LDO) testing:
    http://www.badcaps.net/forum/showthr...999#post300999

    Inverter testing using old CFL:
    http://www.badcaps.net/forum/showthr...er+testing+cfl

    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
    http://s807.photobucket.com/user/budm/library/

    TV Factory reset codes listing:
    http://www.badcaps.net/forum/showthread.php?t=24809

    Comment

    • Teeva
      Member
      • Oct 2014
      • 14
      • usa

      #3
      Re: HP L1906 fixing (pictures and steps)

      Originally posted by diodine
      An old non working HP L1906 monitor was given to me two or three months ago, as crap to be dumped. I have searched the forum and I have found there are at least three versions of this same electronics and no reference to the steps to open the box.

      So now I am writting this post to help others. Firstable I want to copy here the opening steps, as written in an hp forum by an angry user. In no way I am subscribing necessarily his(or her) expressions about hp, the monitor, etc , but I won't change a word because it is his/her work :



      Mine had exactly 3 caps numbered C822, C823 and C824, 1000 uF 10 V CapXon, vented off and not working. The monitor didn't power on. The fixing consisted in desoldering of the old three and soldering of three new Daewoo same specs but 16V. The monitor started at first try and has worked several hours with no problems.

      Here are the pictures, I expect them to be useful.

      I also am attaching the service manual I have found, although it does not seem to address the problem this monitor had (or at least not in the way I made).
      The link below is the instructions how to take the monitor apart.

      Comment

      • diodine
        Member
        • Dec 2011
        • 46
        • Spain

        #4
        Re: HP L1906 fixing (pictures and steps)

        Originally posted by budm
        Please make sure to use LOW ESR type caps not general purpose type otherwise it may last weeks or months since the power supply is running 24/7 even when you turn off the monitor.
        http://s807.photobucket.com/user/bud...in=true&page=1
        Thank you, budm for your great pictures and wise words. My fix was a quick and dirty (and cheap, 0.39 €) one, my local e-shop did not let me choose the caps. But after reading the datasheets I see that tan delta for CapXon KF 10 V is about 0.19, and for the Daewoo RMU it is about 0.24, not as far a difference as it could be. Obviously, using low ESR Daewoo RUF you meet a tan delta of about 0.10, much better.

        Perhaps a more critical factor is the leaking current, what seems to differ in greater proportion. IDK.

        If it breaks soon, I will change all the electrolitics that you note with some good ones from ebay.

        Originally posted by Teeva
        The link below is the instructions how to take the monitor apart.
        TY, Teeva, for your link, but that instructions have no sense for taking apart my monitor. Perhaps they are for another, older (2004), version of it.

        Comment

        • selldoor
          Slow Learner
          • Dec 2010
          • 7870

          #5
          Re: HP L1906 fixing (pictures and steps)

          Perhaps update your profile with country and voltage.
          We do not normally recommend buying caps from ebay except from a few trusted outlets.
          There are many fakes about and even the sellers do not know what they sell.
          Please upload pictures using attachment function when ask for help on the repair
          http://www.badcaps.net/forum/showthread.php?t=39740

          Comment

          Related Topics

          Collapse

          Working...