Announcement

Collapse
No announcement yet.

Samsung 245BW, No Power, No LED (Sometimes works, mostly doesn't)

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

    Samsung 245BW, No Power, No LED (Sometimes works, mostly doesn't)

    Greetings everyone!

    I apologize for the amateur post. I have been lurking on these boards for the past week as I've dealt with recent issues of my Samsung Syncmaster 245BW. It would appear that this monitor is prone to some common specific issues and I have tried to follow along with other suggestions in other threads, but have come up short.

    The monitor was working fine up until a few weeks ago when it suddenly started being fussy about being turned on and off. It works fine when it is powered on, but it began to not power back up when pressing the power button on the front. When this happens, the screen stays black, the blue led on the power button does NOT light up, and it would appear to be totally inert.

    Interestingly, if you let it sit for long enough (and this time period seems to have grown longer and longer so that now it doesn't seem to work at all) and then went to power it on, sometimes it would turn on just fine and would be usable until the next time it was powered off. Then it won't power up again.

    So I did some research and quickly realized the power board frequently has bad capacitors and some select faulty resistors. Initially, I just replaced the two most commonly faulty capacitors that were visibly bulging with some leakage on top. I put everything back together and it was still totally unresponsive so I almost considered it scrap then. Lo and behold, the next morning I come out and the monitor is on. At this point I was completely clear if the replacing of the two faulty capacitors did the trick, but it made me feel slightly more confident about me not making things worse via repair error. Unfortunately, I had to power it off as I moved it back to my desk, and of course it wouldn't turn back on once I had it in position.

    This led me to pick up some some 68ohm resistors to replace the three that are often faulty in addition to two more capacitors to swap out. I just finished replacing all these parts, put everything back together, and still am striking out.

    At this point I'm about ready to settle for buying a new power supply board via eBay for $50 as was mentioned in another thread, but I'm also concerned that it might not be the problem.

    I have very limited electrical engineering knowledge and am completely self-taught as far as saudering irons and multimeters go although I now own both tools. I'm also aware that the pros would like pictures of the power supply uploaded as well as the model number, etc. I'll add those tomorrow, but I'm burnt out on working on it for tonight aside from writing this post.

    I appreciate any and all help and I apologize if this just seems like another repeat thread. I used the search option and went through the threads that came up, but most of them were issues with the screen staying black, but the blue LED *does* come on, where in my case, it *does not*.

    Again, thank you!
    Nathan
    Last edited by SpaceNurse; 09-18-2012, 11:50 PM.
    Tags: None
    #2
    Re: Samsung 245BW, No Power, No LED (Sometimes works, mostly doesn't)

    Originally posted by SpaceNurse View Post
    Interestingly, if you let it sit for long enough (and this time period seems to have grown longer and longer so that now it doesn't seem to work at all) and then went to power it on, sometimes it would turn on just fine and would be usable until the next time it was powered off. Then it won't power up again.

    Initially, I just replaced the two most commonly faulty capacitors that were visibly bulging with some leakage on top.
    1) Your description in the first paragraph above is likely capacitors that have high ESR (ohms). As the monitor warms up, the cap's ESR drops allowing the lcd to work.

    2) Like so many others, you are making the all too common assumption that bad capacitors bloat. Think of an AA battery. If the AA battery is leaking crud, you know it is bad. However, can you tell, without test equipment, that an AA battery with a "best before" date of April 2019 is good or bad by just looking at it?

    3) See my standard capacitor replacement answer below (regulars may skip)

    https://www.badcaps.net/forum/showpo...4&postcount=19

    4) Do you have a multimeter and do you know how to measure DC voltage?
    Last edited by retiredcaps; 09-19-2012, 12:37 AM.
    --- 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 245BW, No Power, No LED (Sometimes works, mostly doesn't)

      I really appreciate the quick reply retiredcaps, thank you.

      I think I understand your first statement at this point, your link also clarified things quickly. I don't think I was making the assumption that all capcitors bloat, that was just what I was directed to on my initial youtube search of common 245bw problems. And hence when I opened the thing up for the first time and saw two visibly busted capacitors, I had hoped it would be as simple as that. Sadly, that was not the case.

      I'm going to go ahead and admit right here that the recent capacitors that I put in I purchased from RadioShack when I picked up a multimeter and saudering iron. I'm in school right now and was trying to fix things quicker than later, although I'm sure at this point I'll go ahead and order a bunch of quality capacitors as suggested in your guide.

      I do have the small digital multimeter I bought recently and know how to operate it, but don't really have the concept of the science behind it, I'm working on educating myself on that as well as on how to sauder. It definitely just seems like something that comes with practice and once again I'm using a cheapie from RadioShack.

      Speaking of which, is there a type of sauder that is considered a good balance between price and performance? Does it really matter that much for my simple applications?

      Thanks again!

      Comment

        #4
        Re: Samsung 245BW, No Power, No LED (Sometimes works, mostly doesn't)

        Originally posted by SpaceNurse View Post
        I'm going to go ahead and admit right here that the recent capacitors that I put in I purchased from RadioShack when I picked up a multimeter and saudering iron.
        RadioShack is unlikely to sell low ESR capacitors which are required in a SMPS environment.

        RadioShack likely sells general purpose caps. The difference between the two is the general purpose caps are likely to have an ESR (ohms) that is 10x higher.

        I do have the small digital multimeter I bought recently and know how to operate it, but don't really have the concept of the science behind it, I'm working on educating myself on that as well as on how to sauder.
        I started by watching many youtube videos. I'll make it simple for you and give you the benefits of all my hours of research.

        http://www.youtube.com/watch?v=I_NU2ruzyc4

        http://www.youtube.com/watch?v=bF3OyQ3HwfU

        These are the 2 best videos wrt to soldering and multimeter usage for beginners. Note the spelling of soldering. You won't find any info with the way you spell it.

        Speaking of which, is there a type of sauder that is considered a good balance between price and performance? Does it really matter that much for my simple applications?
        Any traditional 60/40 solder with flux will do. RadioShack is a good place to buy 60/40 solder.
        Last edited by retiredcaps; 09-19-2012, 01:48 AM.
        --- 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 245BW, No Power, No LED (Sometimes works, mostly doesn't)

          If you are still at school ?/, do they not have someone who is in charge of its IT facility,and may well be able to help with soldering etc etc.

          Comment

          Previous template Next
          Working...
          X