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    #1

    hp w2338h issue

    Hi all, I've lurked around the outskirts here getting valuable information and now I need help.

    I have an HP w2338h, that came to me with the 2 second to black problem. (I guess i should say first that I have successfully fixed quite a few dead monitors already, thanks to you guys, but this was my first hp)

    So here is what puzzles me. I opened it up and found "elite" caps, none of which looked bad but identified on here as suspect, and I replaced them with nichicons from my local electronics supply store. same size and values.

    When I put the monitor back together, about the time it should light up, I have a bright flash on the screen, which goes away, and no display at all. I have recheck all polarities and my soldering. (BTW I have over 20 years experience in high tech development and don't usually make dumb mistakes, but I am getting older so....)

    So with the monitor disassembled I lay out the boards so i can see what's going on, and i see arcing at the ccfl, top left corner back of lcd assembly. I honestly cannot remember but I think I heard this prior to disassembly.

    So my questions are the following:

    In your troubleshooting guide the comment is made that 2 seconds to black usually indicates good ccfls, did I misunderstand this?

    Since the ccfl circuit has over current protection, if some of my "new" parts are bad, would I see an arc prior to shutdown?

    Is there some easy way to test ccfls, without taking the screen apart, or having a spare ccfl to use as a tester?

    And of course, any questions I might have forgotten that you folks can come up with to help me out.

    What really bothers me about this is that I had a display before, and now I don't. I don't want to think I broke this by fixing it!
    Tags: None
    #2
    Re: hp w2338h issue

    The arcing may be due to burnt up wire that may be barely connected to the lamp's end.
    You may be able to tug on the iwre, but not at bothe ends of the lamp assembly, so it will require you to take it apart. You can see example of bad CCFL here:
    http://s807.photobucket.com/albums/y...klight%20lamp/

    I also use test lamps for inverter function test.

    http://s807.photobucket.com/albums/y...g%20old%20CFL/
    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

      #3
      Re: hp w2338h issue

      Hey, Thanks for the quick response. I had forgotten that I did have an old samsung laying around and i went and swapped the lamps for the upper (bad) lamp on the HP, and no arc and now there is a display. So once I fix the lamp this baby should be fine. Anyone know offhand which lamps this model takes?

      Comment

        #4
        Re: hp w2338h issue

        I think you may have mis read/mis understood - Its only if all the tests are passed that it is not a faulty ccfl.

        All known tests are covered in the guide - re read Posts 19/20 5) Bad CCFL/wiring.

        The wiring gets very brittle so moving the thing about more than usual could have caused the change. If you can pin point where the arcing is perhaps you can rig some temporary insulation then you can decide next course of action. You seem to have established where the main fault lies and there is no easy fix.

        Lots of info at lcdparts.net. -
        Please upload pictures using attachment function when ask for help on the repair
        http://www.badcaps.net/forum/showthread.php?t=39740

        Comment

          #5
          Re: hp w2338h issue

          Originally posted by nedonedo View Post
          In your troubleshooting guide the comment is made that 2 seconds to black usually indicates good ccfls, did I misunderstand this?
          You misunderstood.

          I wrote that guide by compiling a lot of information from regular contributors like PlainBill, alexanna, and jetadm123. For the next revision, I usually re-read everything with "fresh" eyes and will see if I can make that section a bit more clear.

          I already have contributions from others like budm, selldoor, and others to incorporate. I usually wait a few months so I get a "fresh perspective" and monitor all the 2 seconds to black threads to see what the feedback is.
          Last edited by retiredcaps; 05-18-2012, 05:23 PM.
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          Comment

            #6
            Re: hp w2338h issue

            I thank you all for your input! The top lamps are bad, both broken in two. Evidently the caps had failed enough that the normal shutdown didn't. With new parts, working correctly, the system did what it was supposed to for the condition of the lamps.

            retiredcaps, THANK YOU! Your guide has been very helpful in the past and i look forward to any additions or revisions that you may do. And so no one is left out, all of the contributers here provide excellent information and almost everything I have learned about flat screen monitor, and motherboard repair, I have learned here

            Having now disassembled the screen, I have to admit, i was being lazy, and hopeful that I wouldn't have to.

            So once again, anyone know what lamps this hp w2338h takes?

            Comment

              #7
              Re: hp w2338h issue

              Originally posted by nedonedo View Post
              So once again, anyone know what lamps this hp w2338h takes?
              Members have excellent feedback for the people at

              ccflwarehouse.com

              You can phone them and they will tell you exactly what size is required for the monitor.

              ccfldirect.com is another choice if you want some alternatives.
              --- 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

                #8
                Re: hp w2338h issue

                ccflwarehouse.com sells bare or pre-assembled/pre-harnessed. The latter is obviously more expensive, but easier to replace. The former requires patience, a delicate touch, and patience.

                See

                http://www.ccflwarehouse.com/lasotu.html

                I estimate that about 50% of the people who try the bare lamp method fail because they lack patience and break the ccfl by trying to force it in.

                I have a couple of 17 inch monitors that have bad ccfls. Since an used one only sells for $20 at most, I don't even bother repairing these and keep them around as test subjects or parts.
                --- 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

                  #9
                  Re: hp w2338h issue

                  Reading through another thread here on this monitor I found that plainbill ended up with one and listed the length as 535mm. Unfortunately cfl warehouse has two different diameters for this length, so I sent them an email and will post actual size (and part number) when I get it.

                  Thanks again to everyone!

                  Comment

                    #10
                    Re: hp w2338h issue

                    Good Morning,

                    I just went through the same issue with the same monitor. The unit would shut down after a second or two. It produced a easily audible buzzing, and a very noticeable stench. Upon opening the monitor, I found that there was arcing from the CCFL inverter connector (attached to the CCFL). The current was so high that it melted a hole in the connector, followed a path back out of the receiving connector (female, mounted to the power board) and was shorting to one of the grounding pins.

                    I disassembled the LCD panel so I could view the lamps and retested. I noticed one of the CCFL's was dark, the second in the pair (this panel has 4 lamps, 2 top and 2 bottom) just flickered. I temporarily replaced the faulty CCFLs with a couple I had lying around from an LCD TV. When I applied power again, the lamps lit up, but went out after a couple of seconds. The arcing was still an issue. I verified that the board mounted receiving connector wasn't damaged, but the male wire-end connector was scorched and had a hole melted through the side of it. I couldn't find replacements for the 4-pin connector, but realized that it was just to of the standard 2-pin connectors bridged together to form a single connector. I took a known bad panel (cracked screen) and cut off the connectors. I soldered the two of them in place of the single connector. Hooked everything up and applied power again. This time the lamps lit and stayed lit.

                    I measured the CCFLs that I had removed and they measured 520mm from end of glass to end of glass, not end of connector to end of connector. That may be where the extra 15mm is coming from to get the 535mm. I'll double check tonight before I place an order. I have found 520mm lamps on Ebay. They are the 2.6mm versions. I have emailed the seller for more information as well (he's asking $10ea. + 4.99 shipping).

                    I also found that ccfldirect has a kit to replace all four lamps for $24.99 + $3.99 shipping. I think it makes sense to spend the extra $10. This seems to be a fairly common problem, and to have to do this fix again would cost more than the kit.

                    Good luck with your repair! I'll try to post a couple of photos of that connector later tonight.

                    P.S. I have to say this just to make me feel better. I picked this monitor up at a yard sale along with an HP wireless all-in-one for $5. Cha-ching!


                    -Grant

                    Comment

                      #11
                      Re: hp w2338h issue

                      Here's a closeup of the connector
                      Attached Files

                      Comment

                        #12
                        Re: hp w2338h issue

                        Xwell, thanks for the info. I am still in limbo here, because my lamps are broken, I have not pulled and measured them. ccfldirect was not able to give me the correct dimensions for this monitor and i need to measure before ordering.

                        If I get correct part info I will post, and if someone else does first, i will be grateful!

                        Comment

                          #13
                          Re: hp w2338h issue

                          This post: https://www.badcaps.net/forum/showthread.php?t=16005
                          suggests yet another size 525 x2.4 mm
                          Please upload pictures using attachment function when ask for help on the repair
                          http://www.badcaps.net/forum/showthread.php?t=39740

                          Comment

                            #14
                            Re: hp w2338h issue

                            OK, I got the 520mm lamps in yesterday, and they are very close, maybe a millimeter or two long. But now, when I have all four lamps wired in, I get two that light brightly, and two that are a bit dimmer. they appear to attempt to come up to full brightness, then they all go out. I need to do some swapping around to see if I can pinpoint the issue.

                            Comment

                              #15
                              Re: hp w2338h issue

                              Just to get it clear - is that four new bulbs or two new and two old?
                              Please upload pictures using attachment function when ask for help on the repair
                              http://www.badcaps.net/forum/showthread.php?t=39740

                              Comment

                                #16
                                Re: hp w2338h issue

                                Four new

                                Comment

                                  #17
                                  Re: hp w2338h issue

                                  Are the connectors in good condition (the one you have shown in the picture)? The ballast caps are OK?
                                  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

                                    #18
                                    Re: hp w2338h issue

                                    ok how long are they on before they go off.? Have you got a source connected.?
                                    Do you get a picture?
                                    Please upload pictures using attachment function when ask for help on the repair
                                    http://www.badcaps.net/forum/showthread.php?t=39740

                                    Comment

                                      #19
                                      Re: hp w2338h issue

                                      I replaced both of the double connectors with four single (standard) connectors. I have the lamps wired up with jumpers right now, not soldered, to allow me to easily switch the lamps around. Could that be causing a problem? I didn't get a chance to work on them last night, but I plan to do some testing tonight. However, I don't think it's the lamps as I can swap them around and the result is the same. Is it possible that the new lamps have a different rating than the originals, therefore the inverters are sensing something out-of-range?

                                      I've got v3 of the "2-Seconds-To-Black" guide compiled by RetiredCaps, and plan on working my way through it tonight. Originally, the current was shorting through the connector inverter #1 (photo above), and on inverter #2 the arcing was taking place across the traces on the back of the PCB. This leads me to believe that I could have a shorted/damaged component somewhere. I haven't done any testing in that arena (caps, transistors, fuses, etc.) up to this point.

                                      Selldoor, I don't currently have any source connected, and the panel is still disassembled. I could hook up the controller connections (input source and TFT panel) if you think that could be the issue.

                                      The lamps shut off after only a couple of seconds. Back when I initially tested the panel, I replaced the bad pair of lamps with a couple I had lying around from a 32" TV. They lit up correctly (all four), and I let them stay on until the monitor went to sleep due to no input. But that took at least a minute, and the power LED changed from blue to orange.

                                      Thanks for all the help so far!

                                      Comment

                                        #20
                                        Re: hp w2338h issue

                                        As you guess I was thinking monitor sleeping due to lack of input, but its going off too quick for that.
                                        Normally before now I would have suggested testing the
                                        inverter transformers -but as at one point you had all 4 staying on it seemed unlikely to be a problem. It is outlined in the 2 sec to black guide but after the set has been off for 5 minutes with meter on 2000 ohms check the resistance of the secondary windings and post the results.
                                        They should be ok but perhaps a problem with them may have been disguised by using 32inch tv lamps in the initial test
                                        Please upload pictures using attachment function when ask for help on the repair
                                        http://www.badcaps.net/forum/showthread.php?t=39740

                                        Comment

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