24" Widescreen CRT (FW900) From Ebay arrived,Comments.

Discussion in 'Displays' started by mathesar, Sep 13, 2005.

  1. Meeho

    Meeho 2[H]4U

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    The original seems much better at keeping blacks.
     
  2. Strat_84

    Strat_84 Limp Gawd

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    Well, the screen looks much darker when off because the original film has a lower transmittance than the replacement. But regarding the black depth of the picture I'm not sure if there will be much of an impact as long as a WPB is performed to match the new film transmittance.

    But there isn't much choice anyway, all standard anti-reflection film are designed for maximum transmittance, 92% is already "low". Something in the 60-70% range could only be obtained with a custom manufacturing.
     
  3. XoR_

    XoR_ Limp Gawd

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    maybe these AR filters prevent light reflecting back on phosphor (and instead direct it to front of monitor increasing whites) and that's why they make whites brighter?
    if that is the case then this is a great effect
     
  4. Meeho

    Meeho 2[H]4U

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    Light already passed the glass when it gets to the filter, what would it be reflecting from?
     
  5. XoR_

    XoR_ Limp Gawd

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    Phosphor spot produce light in all directions and some gets reflected internally in glass back to phosphor. This is what produces halo ring effect when you display small bright object on black background.

    JVTCPSH.jpg
     

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  6. Meeho

    Meeho 2[H]4U

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    I get that, but how would an AR filter outside the glass make a difference?
     
  7. Meeho

    Meeho 2[H]4U

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    krótkie wyjaśnienie wystarczy
     
  8. XoR_

    XoR_ Limp Gawd

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    lol, by mistake I posted something I was writing to someone
    I was wondering why it didn't show in the right place :p
     
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  9. Strat_84

    Strat_84 Limp Gawd

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    Alright, first attempt to fit the AR film today ... and I wasted a sheet. :dead:

    But I guess that was expectable.

    - First mistake: removing the protection layer on too much surface in the beginning. That thing is the devil and once a part is stuck, the rest follows slowly if you don't pay attention. You end with monster bubbles you can't get rid of..
    - Second mistake: pressing too hard when applying the rest of the film, that scratched the AR layer. I used a soft rubber tool and more or less the same technique as in this video:


    - Third mistake: using kitchen towel to make sure again there is no dust on the glass before sticking a section of film. But I ended sticking some paper on the adhesive. The plastic film protecting the adhesive actually rubs the glass when getting removed and should catch any dust still there. The best is the enemy of the good. :rolleyes:

    Well, at least I was successful in cleaning the glass. A rubber helps removing any adhesive still sticking here and there. Then alternatively water with a sponge, dry with a kitchen towel, isopropylic alcohol with a kitchen towel, then a dry kitchen towel again with turning movements to get rid of any stain. I tried using a cotton piece of cloth, bad idea, it seems to leave some micro scratches.
    I'm wondering if I won't try wet application next time. It may be a bit easier.
     
    Last edited: Jun 21, 2018
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  10. Petrasescu_Lucian

    Petrasescu_Lucian n00bie

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    Has anyone tried the Delock 87685? Does it have the same issues as the Sunix splitter?
     
  11. bhtooefr

    bhtooefr n00bie

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    I wonder if this VM2322 firmware update would work on the Sunix devices: https://download.lenovo.com/pccbbs/mobiles/fwdphb07.exe

    (Make sure a monitor's plugged into the Sunix device before running that.)

    Also, if you do try it, might be a good idea to run it in a command prompt with the -v flag (so fwdphb07 -v), and then look at the contents of update.log, that'll say what version's on the device, before you reflash it.
     
    Last edited: Jun 30, 2018
  12. bramabul5353

    bramabul5353 [H]Lite

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    Anyone Looking for a New D-Board with Flyback PM me. I sold both my FW900 monitors and I am looking to sell this part. Brand new in box.
     
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  13. Strat_84

    Strat_84 Limp Gawd

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    A little update regarding films. After a few tests on small pieces I finally applied another sheet with a wet method this time. I still need to let it dry before checking if everything is alright. Answer probably in the end of the week. ;)
     
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  14. Meeho

    Meeho 2[H]4U

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    Do these improve blacks during daylight?
     
  15. Strat_84

    Strat_84 Limp Gawd

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    I wonder why you ask that question. The very purpose of an AR film is to cut reflections, i.e. interferences of external light sources with the screen. If the daylight interferes with the picture (not just black, the entire picture), then an AR film will improve it of course.
     
  16. Enhanced Interrogator

    Enhanced Interrogator Gawd

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    Interesting find.
     
  17. Meeho

    Meeho 2[H]4U

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    Because it doesn't seem to do much from your pictures here.
     
  18. Strat_84

    Strat_84 Limp Gawd

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    Picture one -> the effect of the piece of the AR film on reflections is pretty obvious
    Picture two -> You'll notice the black lines are a little darker in the area with a film, than the one without, and it has most probably nothing to do with daylight BTW. It's because the film has a transmittance below 100%, and the G2/brightness aren't set properly.
    Picture five -> there's a clear difference of appearance between the original film and the replacement when the screen is off. But you're just seeing the phosphors through a dark film on one side, and a less dark film on another side. This has nothing to do with the performances when the screen is on.
     
  19. Meeho

    Meeho 2[H]4U

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    The screen doesn't become darker when the display is on. There is a stark difference in black level with ambient light as seen in you picture. So much so that I don't see much benefit from the films you're testing. They don't seem to be an adequate replacement for the original AG.
     
  20. jrodefeld

    jrodefeld n00bie

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    I've already PM'd this guy, but I wanted to ask a question of everyone else.

    I have an extra FW900 in my closet that has a bad Flyback transformer. I'd sure like to repair it if possibly and new flybacks are going to be hard to come by.

    The problem is how to replace it.

    I've heard enough about the dangers of working on CRTs and I don't think I have enough experience to risk trying this repair myself.

    I guess I could find a technician to do it, but could I even find someone with experience repairing CRT monitors nowadays? And how much would someone charge for this simple repair?

    In case anyone suggests it, I can't take this to Unkle Vito. I live too far away and he'd probably charge more than I'm willing to spend right now.

    Thanks.
     
  21. Strat_84

    Strat_84 Limp Gawd

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    The problem is that everytime something goes wrong on a CRT monitor, someone comes and say "Meh, the flyback is dead". Most of the time I bet the flyback is perfectly fine.

    IF you have an issue with the flyback or a component in the vicinity and you get another D-board, it's pretty easy to repair. Just swap the boards. Don't forget to put thermal paste between the D-board's heatsink and the support plate. Then you may have to adjust the focus potentiometers and you're probably good for a full Windas adjustment procedure.

    N;B: There's no special danger as long as the monitor is unplugged and you have waited for capacitors to discharge (a few hours should be enough, but you can wait a few days if you want to play that safe)
     
    Last edited: Jul 12, 2018 at 5:43 AM
  22. Enhanced Interrogator

    Enhanced Interrogator Gawd

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    How sure are you about this? I've heard quite the opposite.
     
  23. Strat_84

    Strat_84 Limp Gawd

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    Well, what did you hear ? It's electronics, not magic. Electricity is the risk and it has to come from somewhere. Once it is discharged there is no risk at all. Of course it's a completely different story if someone messes inside while the monitor is plugged and/or powered,
     
  24. Enhanced Interrogator

    Enhanced Interrogator Gawd

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    I remember hearing the larger capacitors and even the tube itself can hold a charge for months. Don't remember where I heard it but I've been super cautious ever since
     
  25. Strat_84

    Strat_84 Limp Gawd

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    I read that here and there too. Apparently relatively new CRTs like those Trinitron *would be* fast discharging and much safer than older ones. But what is an "older one", I don't know for sure. At least I've manipulated the boards a lot during my investigations, and the worst I have seen is a little spark when shorting a 200V + section and not having waited long enough. Impressive when you don't expect it but not really harmful.

    If someone isn't used to dismantling such monitor though, IMO the advice is to wait a few days powered off and unplugged, so that he can play around comfortable, without shitting his pants. More than a week isn't necessary nor practical.

    The really dangerous part is the anode cap since the voltage reaches up to 10-15kV there. But then, some advices are actually idiotic. I've seen advised to take an insulated screwdriver connected to the ground, and to slide it under the anode cap before removing it, in the name of safety. And that's how you scratch the insulated coating on the tube ... The service manual of the FW900 clearly describes what to do: removing the anode cap, how to do it holding the rubber insulated part, then grounding the anode in case there is still a charge.