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leperinc
Member
Last Activity: 04-25-2019, 10:37 AM
Joined: 01-04-2011
Location: ottawa, canada
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight

    The parts from China finally arrived! removing the dead chips was a bit easier than I expected. I didn't expect the chips to be glued to the board, however the chips were hot and the glue was fairly soft. Soldering the new ones on went well. We now have a backlight. It's alive! Another one saved from the landfill.

    Jetadm123 and retiredcaps: thank you very much for your help with this. If you're ever in the Ottawa area I owe you a beverage of your choice!

    ...
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    Last edited by leperinc; 02-17-2011, 09:54 PM.

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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight

    Alexanna, I looked at your pic of the underside of the power supply board and I'm assuming U202 and U203 have been replaced because they have no obvious burns on them, U203 doesn't look like it's soldered correctly (or it could be the lighting.. )

    carry on...

    update: still waiting for my parts...
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight


    <smacks head> Thanks for pointing that out! I've placed the order, so now we wait...

    ...
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight



    They all look fine. No opens or shorts.



    I wasn't able to find the original part at any of the usual places. Elsewhere in the forum here i saw a couple of people claiming success with a MMDF2C03HD from another manufacturer. A quick search shows Mouser is currently the only supplier with stock in individual chips at $1.47 each.

    However, at $20 shipping, this last item is too expensive for me to continue. Getting this far has cost me $31. I'm currently not working and getting the parts from...
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    Last edited by leperinc; 01-16-2011, 01:25 PM. Reason: I accidentally a word out

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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight

    No problem, I appreciate your help with this. I'd like to hedge my bets on this one and ask what other components might be needed in case U202/3 are fine. I'd rather spend $5 in extra parts now as insurance rather than having to spend yet another $8 on shipping later.

    Thanks!
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight



    Sorry about that, there are no opens or shorts no matter what pins/directions I measure.

    here's the pic:...
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight


    i'm going crosseyed. I can't find it. Can you point it out to me?...
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight

    I figured I'd kill some time and poke around on U201 and measure everything from anywhere to anywhere in both directions. There appears to be one short between pin 7 and 16. I'm not sure if this is normal or not. On the similar model (3193) sheet pin 7 is GND and pin 16 is MODSEL. C345 (33uF/35v, replaced) is connected by traces across pin 7 (GND) and 10 (VCC)
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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight



    I don't see a U301, I'll assume U201. I tried looking up the datasheet on it and can only find the [url=http://html.alldatasheet.com/html-pdf/241688/ETC/BIT3193/114/2/BIT3193.html]BIT3193[/url]. Is this close enough, and what pins should I be paying attention to for measuring?

    I see 13Volts on CN2, yes.



    There is also 13volts on the center of D105. I've tried to clean the chips, first with my fingernail, followed by a white eraser and rubbing alcohol but it didn't change anything....
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    Last edited by leperinc; 01-15-2011, 06:41 PM. Reason: added burnmarks.jpg

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  • leperinc
    replied to Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays
    Re: Samsung 930B re-capped, no backlight



    Thanks for the reply.


    I put the black lead on the first point mentionned and the red lead on the second i.e. black to S1 and red to G1, etc. It's hard to see so I've included a pic pointing to what I think is pin 1. Hupefully I've gotten it correctly

    I've checked both U202 and U203 and they read identical.

    S1 --> G1 = 2.5K ohms
    G1 --> D1 = 30K ohms
    S1 --> D1 = 700 ohms
    S2 --> G2 = 400 ohms
    G2 --> D2 = 100 ohms
    S2...
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  • leperinc
    started a topic Samsung 930B re-capped, no backlight
    in Troubleshooting Computer Displays

    Samsung 930B re-capped, no backlight

    A while ago I was given a dead Samsung 930B and made an attempt at fixing it by replacing the obviously damaged electrolytic caps. On my first attempt i replaced:

    cap# orig uf/v ---> new uf/v
    -------------------------------------------------
    301 820/25 820/25 nichicon pw
    111 820/25 820/25 nichicon pw
    112 820/25 820/25 nichicon pw
    109 1000/10 1000/25 nichicon pw
    110 1000/10 1000/25 nichicon pw

    When I pressed the power button the green LED stayed on followed by a high pitched screeching noise coming from everywhere on the board....
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    Last edited by leperinc; 01-14-2011, 06:14 PM. Reason: formatting
  • leperinc
    replied to New Members - please post your introductions here
    in Announcements & Related News
    Re: New Members - please post your introductions here

    hello from canada!

    i'm more of a software guy... i found this site when looking up the model of a "free" monitor i got...
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