Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]

Announcement

Collapse
No announcement yet.

Samsung Syncmaster 920n white screen

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    Samsung Syncmaster 920n white screen

    Hello
    I have this Samsung Syncmaster 920n who powers on, but only backlight - screen is white and there is no image. I've recapped the PSU, replaced 2x 820/25 1x 330/25 using new decent caps - no luck. I've also read here that some similar models need replacing a fuse which I just can't find. Anyway, here's a picture, any ideas? Better resolution on request.

    Btw this is for my old mother, have heart :o
    Attached Files
    Tags: None
    #2
    Re: Samsung Syncmaster 920n white screen

    was the white screen the orginal problem you were trying to fix?
    Al.
    Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

    Comment

      #3
      Re: Samsung Syncmaster 920n white screen

      A white screen is generally caused by a blown fuse on the LCD panel control board. In your case, it's the long horizontal board (marked Hannstar) just above the power and logic boards. It will be a small surace mount fuse marked something like F1.

      Comment

        #4
        Re: Samsung Syncmaster 920n white screen

        Yes, white screen was before and after. Also, same when I disconnect long panel control board. On it, there is one named F200 (as far I see, only one marked with Fxxx there). How to safely check if it is the culprit (it does not look busted)? What specification fuse do I replace it with? No need to look too professional, I might solder an external one.

        Also, there is an element R209 that looks like it could be busted - but not too much.

        Comment

          #5
          Re: Samsung Syncmaster 920n white screen

          Originally posted by zhilla View Post
          Yes, white screen was before and after. Also, same when I disconnect long panel control board. On it, there is one named F200 (as far I see, only one marked with Fxxx there). How to safely check if it is the culprit (it does not look busted)? What specification fuse do I replace it with? No need to look too professional, I might solder an external one.

          Also, there is an element R209 that looks like it could be busted - but not too much.
          Simply continuity test. Very low (under 1 ohm) is good, open is bad. What are the markings on the fuse? Also, look on the PCB near the fuse -- sometimes they silkscreen the ratings.

          Comment

            #6
            Re: Samsung Syncmaster 920n white screen

            Detailed images of the region
            Attached Files

            Comment

              #7
              Re: Samsung Syncmaster 920n white screen

              Originally posted by zhilla View Post
              Yes, white screen was before and after. Also, same when I disconnect long panel control board. On it, there is one named F200 (as far I see, only one marked with Fxxx there). How to safely check if it is the culprit (it does not look busted)? What specification fuse do I replace it with? No need to look too professional, I might solder an external one.

              Also, there is an element R209 that looks like it could be busted - but not too much.
              You are misreading the component identifcations. R209 is above the label. This is a diode, the exact designation is obscured by the arrow you drew.

              PlainBill
              For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

              Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

              Comment

                #8
                Re: Samsung Syncmaster 920n white screen

                I just noticed my mistake myself It is indeed marked D100. My multimeter has diode test mode and it shows values of around 1.000-1.050 (are those V?) in both directions. Does that mean its busted?

                Fuse F200 measures less than 1 ohm, that means it works?

                Comment

                  #9
                  Re: Samsung Syncmaster 920n white screen

                  Originally posted by zhilla View Post
                  I just noticed my mistake myself It is indeed marked D100. My multimeter has diode test mode and it shows values of around 1.000-1.050 (are those V?) in both directions. Does that mean its busted?

                  Fuse F200 measures less than 1 ohm, that means it works?
                  I'm not aware of any diode that has a drop that high. On the other hand, it's unusual for a diode to go open. I'd remove it from the board and check it out of circuit, or if the marking code is visible, try to identify what it is.

                  A reading of less than 1 ohm means the fuse is good.

                  PlainBill
                  For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

                  Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

                  Comment

                    #10
                    Re: Samsung Syncmaster 920n white screen

                    So D100 does look burned. Also, it shows about 1.5 in both directions. This is a HSD190ME12-A11 panel. Any ideas about a replacement?

                    Comment

                      #11
                      Re: Samsung Syncmaster 920n white screen

                      Can you please list the exact capacitors (Company and Series) that were there before and also what did you use to replace them?
                      "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

                      -Leonid Brezhnev (On the Yom Kippur War)

                      Comment

                        #12
                        Re: Samsung Syncmaster 920n white screen

                        Yes. i replaced 2x 820uF/25V Capxon with same spec KZH. 1x 330/25 Capxon with 330/35 KSC.

                        Comment

                          #13
                          Re: Samsung Syncmaster 920n white screen

                          At http://www.sharefx.net/monitor-repai...sd190me12-a10/ I found this info:
                          This sounds reasonable. These are around EL7581 chip, and according to spec here:

                          That should be Schottky diode MBRM120LT3 (20V 1A). Would MBRM120ET1 be a compatible diode (which I can find on Ebay)?

                          Comment

                            #14
                            Re: Samsung Syncmaster 920n white screen

                            Originally posted by zhilla View Post
                            At http://www.sharefx.net/monitor-repai...sd190me12-a10/ I found this info:
                            This sounds reasonable. These are around EL7581 chip, and according to spec here:

                            That should be Schottky diode MBRM120LT3 (20V 1A). Would MBRM120ET1 be a compatible diode (which I can find on Ebay)?
                            I believe so.

                            PlainBill
                            For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

                            Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

                            Comment

                              #15
                              Re: Samsung Syncmaster 920n white screen

                              Originally posted by zhilla View Post
                              So D100 does look burned. Also, it shows about 1.5 in both directions. This is a HSD190ME12-A11 panel. Any ideas about a replacement?
                              Is this out of circuit or in circuit? If in circuit, take it out and measure again.

                              Also, what are the marking on U100? I believe this would be the DC-DC converter/controller IC.

                              Comment

                              Previous template Next
                              Working...
                              X