Announcement

Collapse
No announcement yet.

Samsung syncmaster 710v

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

    Samsung syncmaster 710v

    Hi all,

    This is my first post, just spent ages looking around this section at faults to see if i can shed some light on my problem! i know some electronics and know my way around around a pcb lol


    anyhow, heres what iv got/found/done etc

    monitor powers up with display then after a minute (or seconds the longer its been on) the screen turns off, power light stays on!

    now i'v found the bad power caps (2x470uf, 1x1000uf, 1x330uf) power is ok (+13v and +5v to video card and +13v to the inverter part of board,

    the monitor stayed on for ages last night after changing the caps, then it went off (slight hissing, getting slightly louder before turning off),

    so i set about searching around the board for any voltages dorpping off!

    when the screen goes off i found that a mosfet (AO4422) that looks like it turns the inverters on (0v switching) is ending up with the inverters supply voltage showing up on the negative output side of the mosfet (0v supply on pins S, +6v to turn it on on Pin G, switched 0v output on pins D) see pic

    the only componants i can find between +13v supply and the switched 0v output that could do this is two diodes SS24 (2A 40V Schottky)

    not had time to remove them yet but does this sound right?

    i checked the bulb life using that service menu! 46k hours its been on, it was used in a police station for the cctv lol

    Regs
    Richard
    Attached Files
    Last edited by Mr_Bodgit; 12-22-2010, 03:44 PM.
    Tags: None
    #2
    Re: Samsung syncmaster 710v

    Originally posted by Mr_Bodgit View Post
    now i'v found the bad power caps (2x470uf, 1x1000uf, 1x330uf) power is ok (+13v and +5v to video card and +13v to the inverter part of board,
    What brand and series of capacitors did you use for replacement? In addition, did you replace all the capacitors or just the bloated ones.

    i checked the bulb life using that service menu! 46k hours its been on, it was used in a police station for the cctv lol
    46K is near the end of the useful life of your ccfl tubes.

    Just a quick clarification question. Right now, what does the lcd monitor do when you power it on? Does the power LED stay on? Do you get the screen staying on?

    edit: Forgot to ask you to post clear focused pictures of your board. If you have been reading posts here, you know the format we want it in (via manage attachments).
    Last edited by retiredcaps; 12-22-2010, 04:36 PM.
    --- begin sig file ---

    If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

    We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

    Please do not post inline and offsite as they slow down the loading of pages.

    --- end sig file ---

    Comment

      #3
      Re: Samsung syncmaster 710v

      i took the better looking 470uf and 1000uf ones from another faulty monitor

      yeah i know bad idea but the power supply outputs are ok no matter what happens, +13v and +5v on volt meter, there only smoothing caps as across + & - outputs so cant see it being them.

      the supplies and power LED stay on when the screens tubes goes off, the supply to the inverter part of the board goes to +15v when screen goes off but thats due to less power being consumed i guess

      it stays on for about 10 seconds the starts to hiss slightly near the to diodes i listed

      only the 0v changes to +13v on the supply to 2 transistors marked
      DK
      QL

      i dont have a good camera to post any yet sorry

      Regs
      Rich
      Last edited by Mr_Bodgit; 12-22-2010, 04:58 PM.

      Comment

        #4
        Re: Samsung syncmaster 710v

        Originally posted by Mr_Bodgit View Post
        it stays on for about 10 seconds the starts to hiss slightly near the to diodes i listed
        Everyone has different procedures and starting points. For hiss and given the 47K hours, I would start by looking at the ccfl tubes to see if they are bad or have poor wiring. These pictures will help you determine which is which.

        http://s807.photobucket.com/albums/y...klight%20lamp/

        Alternatively, you can measure the inverter transformer secondaries to see if there is a problem there. This hissing could be coming from there too? This testing requires much less work than the above.
        --- begin sig file ---

        If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

        We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

        Please do not post inline and offsite as they slow down the loading of pages.

        --- end sig file ---

        Comment

          #5
          Re: Samsung syncmaster 710v

          Originally posted by retiredcaps View Post
          46K is near the end of the useful life of your ccfl tubes.
          Not necessarily. Fluorescent tubes are more apt to die from repeat on/off cycles than length of use. If it was used as a CCTV, chances are it wasn't turned on or off that often.

          Granted, 46,000 hours is a lot.
          "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

            #6
            Re: Samsung syncmaster 710v

            Originally posted by mockingbird View Post
            Not necessarily. Fluorescent tubes are more apt to die from repeat on/off cycles than length of use. If it was used as a CCTV, chances are it wasn't turned on or off that often.

            Granted, 46,000 hours is a lot.
            This is where I got my info from ...

            http://ccflwarehouse.com/faqs.html

            Q: What is the typical life of a CCFL lamp?

            A: The typical rated life of a CCFL backlight is 20,000 to 40,000 hours, however when used in LCD applications such as laptops you should expect between 1.5 and 3 years of use from most manufacturers.
            --- begin sig file ---

            If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

            We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

            Please do not post inline and offsite as they slow down the loading of pages.

            --- end sig file ---

            Comment

              #7
              Re: Samsung syncmaster 710v

              Troubleshoot as if it was a 2 seconds to black problem.
              Easiest way I know substitute known good ccfls [if you have them]
              Al.
              Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

              Comment

                #8
                Re: Samsung syncmaster 710v

                tested it with one tube at a time, stays on half the time, bottom tube turns screen pinkish for few second then normal.

                just tried the sceen (just ccfl's) from the other monitor and no hissing or turning off for the min i left it on! CCFL's it is by looks of it, the joys of being given two matching monitors lol i'll swap the power board over and check bulb life on the other one in a min

                regs
                Rich


                update
                other one has 47332Hr
                but its staying on!!!!!!!!!!

                the power board for this screen had the power light coming on but then of wound make a noise and flicker off the back on in a continuous cycle, screen wouldn't light up, as no power for wake up, oh well one out of two isn't bad for nowt.

                cheers guys
                Last edited by Mr_Bodgit; 12-22-2010, 05:26 PM.

                Comment

                  #9
                  Re: Samsung syncmaster 710v

                  Originally posted by Mr_Bodgit View Post
                  tested it with one tube at a time, stays on half the time, bottom tube turns screen pinkish for few second then normal.
                  Pink is sign that the ccfl lamps are nearing end of life. If you want to fix both monitors, ccflwarehouse.com sells bare lamps, pre-wired, and/or pre-assembled. Or you can just be happy with the one fixed monitor and keep the other for spares?

                  If the police used these 24/7, then implies 5.5 years of usage.

                  I haven't commented on the caps yet, but after 5.5 years of 24/7, the original caps may be near end of life too. They don't have to bloat to be bad.
                  --- begin sig file ---

                  If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

                  We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

                  Please do not post inline and offsite as they slow down the loading of pages.

                  --- end sig file ---

                  Comment

                    #10
                    Re: Samsung syncmaster 710v

                    yeah i guess they would, will tinker with the other one over xmas and replace the caps anyway,

                    will look into tubes

                    now i'll be making sure work bring all the old ones back from sites so i can mess with them

                    Regs
                    Rich

                    Comment

                      #11
                      Re: Samsung syncmaster 710v

                      As ccfl lamps age, they draw more and more power. This causes the inverter pwm chip to shut down all the lamps even though only one might be bad (protection).

                      If you are going to order lamps, you have a decision to replace just the "bad" one or all of them. Replacing just the bad one is like replacing the baldest tire, but leaving the other 3 originals on the car (especially since these monitors have > 45K hours).

                      This leads to an economic decision on your part.
                      --- begin sig file ---

                      If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.

                      We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

                      Please do not post inline and offsite as they slow down the loading of pages.

                      --- end sig file ---

                      Comment

                        #12
                        Re: Samsung syncmaster 710v

                        the monitor has been on for hours now and works fine, i'm not bothered about doing the tubes just yet cos we get these all the time so i can just keep tinkering lol

                        but this has got me thinking now becos i have two touchscreen computers that that i got from a steel works and these were on 24/7,

                        the inverters have EMAX PLCD2817418 but IEI / 7F700-PLCD2817418-RS / INVERTER(D->A);4CCFL 7.5MA FOR MEDICAL comes up on net

                        it has a simple 4 wire connection to pc, supply voltage +/- is fine and stays on, not checked the power on/brightness voltage yet but will do later today

                        the screens light up for a few seconds in POST! then go off, turn it off and back on the same happens so i stuck a graffix card in and windows works fine, as does the touch screen

                        just looked at the card and two hermei 150uf 25v caps are swolen and there linked to the mosfets that turn the ccfl's on so i'll start there

                        the 2 ccfl's are 4 wire with two little plugs (my samsung monitors are 3 wire 2 pink, one smaller white so cant use them to test) whats best way and cheapest to test the inverter once the caps are done if it still goes off?
                        Attached Files

                        Comment

                          #13
                          Re: Samsung syncmaster 710v

                          Originally posted by Mr_Bodgit View Post
                          the 2 ccfl's are 4 wire with two little plugs (my samsung monitors are 3 wire 2 pink, one smaller white so cant use them to test) whats best way and cheapest to test the inverter once the caps are done if it still goes off?

                          The style of the connector should not be a problem.
                          Note the orientation of the wires in the connector.
                          It a little extra work but the connectors can be changed, I use a capacitor leg inserted into the small hole of the connector to remove the wiring pigtail from the connector. Then install the pigtail in whatever style connector you need.
                          Al.
                          Attached Files
                          Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

                          Comment

                            #14
                            Re: Samsung syncmaster 710v

                            Originally posted by alexanna View Post
                            The style of the connector should not be a problem.
                            Note the orientation of the wires in the connector.
                            It a little extra work but the connectors can be changed, I use a capacitor leg inserted into the small hole of the connector to remove the wiring pigtail from the connector. Then install the pigtail in whatever style connector you need.
                            Al.
                            what i ment was its a 4 tube inverter, 4x2pin (only pink wires), the sreen i have is only 2 tube, 2x3pin (two pink, one white) whats the white wire for? and can you still test only using the pinks?

                            regs
                            Rich

                            Comment

                              #15
                              Re: Samsung syncmaster 710v

                              Well a pitcure would be hepful,from what i have noted the pink wires are the hot wires the white wire is the return wire.They are most likly sharing the common white wire with more than one ccfl
                              Al.
                              Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

                              Comment

                                #16
                                Re: Samsung syncmaster 710v

                                This is probably not like yours, but it shows how two hot wires share one common white wire
                                Al.
                                Attached Files
                                Last edited by alexanna; 12-24-2010, 09:19 AM. Reason: corection
                                Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

                                Comment

                                  #17
                                  Re: Samsung syncmaster 710v

                                  thats exactly like my samsung one

                                  Comment

                                  Previous template Next
                                  Working...
                                  X