Free 19 inch Dell LCD for repair

Discussion in 'General Electronics Chat' started by maxpower097, Sep 29, 2010.

  1. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    You heard it, I'm in Tampa FL and have a Dell 19 inch widescreen LCD thats free to anyone wanting to repair it. At first you would plug it in and the blue light would just flash as if no signal. Then the blue light quit coming on. Its in mint condition with a nice stand. I'd hate to toss this thing in the dump if someone can repair it and have a nice LCD. PM me if interested. Not sure how bad shipping would be.
     
    Last edited: Oct 1, 2010
  2. tom66

    Senior Member

    May 9, 2009
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    I don't live in Florida so I couldn't collect it. In fact I'm on another continent.

    However, 99% of the time when the monitor will not come out of standby it is due to faulty caps in the PSU. Seriously give it a go - it'll cost $2 max to replace the caps, and you could have a working monitor by the end of the day.
     
  3. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    Whats a PS?



    j/k I may give it a whirl since it is a nice LCD then mine.
     
  4. tom66

    Senior Member

    May 9, 2009
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    PSU = Power Supply Unit.
     
  5. roadey_carl

    Active Member

    Jun 5, 2009
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    Ive fixed 2 samsung lcd screens over the last 6 months! both had the same problem and I replaced the 100uf caps and they work good as new :D
     
  6. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    I'm In Fla Is It still available.
     
  7. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    Ok I got the PSU out and I'm looking at it and I notice 3 Caps that look like they are bulging, or ballooning. The tops are rounded to a degree. Should I test em with the MM or just replace them? And it so happens they are the caps directly connected to a power plug showing B-DIM/+13v/+5.1v/A-DIM/O-F. The 3 caps in questions are
    1. Black KM105 c / C711/ VENT 25v 330uF
    2. Black CapXon 25v / 330uf
    3. Green 1000uF 16v
     
    Last edited: Oct 1, 2010
  8. andrew24

    Active Member

    Aug 20, 2008
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    just replace the caps with the new ones with the same capacity.
     
  9. tom66

    Senior Member

    May 9, 2009
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    Make sure to at least the capacitance. Make the voltage the same or higher. Go for good quality capacitors such as Panasonic or Rubycon.

    Can you post pics of the caps?
     
  10. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    One more issue. I notice what looks like white/yellow ish glue on amany of the disc caps. They look like the glue was intentionally put their for stability. Is this glue? Or are these caps popped and leaked all over the place? It really looks like rubber elmers glue. Pictures coming in the next 2 hours.
     
    Last edited: Oct 1, 2010
  11. tom66

    Senior Member

    May 9, 2009
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    It's glue. You find it in many power supplies.

    Be careful not to touch any high voltage caps. You may see one rated for 200V - be careful it may well have 200V across it (leave the monitor off for about a day before commencing repair.)
     
  12. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    Here are some pics of the suspicious caps.
     
  13. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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  14. tom66

    Senior Member

    May 9, 2009
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    I can't read the cap values but if they match it should be fine.

    Those caps are definitely bulging and probably causing the failure.

    See the 450V cap? Be careful not to touch that. Use a multimeter to check the voltage.
     
  15. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    Yah the specs match. Could I go a lil higher for more protection or stability? And honestly what do you think the chances are that this is gonna fix it?
     
  16. andrew24

    Active Member

    Aug 20, 2008
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    you could definitely go a bit higher on the voltage of capacitors. But the capacitance must be the same
     
  17. tom66

    Senior Member

    May 9, 2009
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    For filter caps you should keep the capacitance the same, but you can vary it a little. You can't put a massive cap on the output because the LC filter will have been designed to cut down on one frequency and this will actually create more noise.

    Do note that the size of the capacitor varies with voltage rating. So you cannot put a 50V cap in the place of a 16V cap, simply because there is not enough space. But you may be able to fit a 25V cap in there.

    The cap voltage ranges are: 6.3V, 8V (sometimes), 10V, 16V, 25V, 35V, 50V, 63V, 80V (sometimes), 100V, 150V, 200V, 330V, 400V, 450V. (Those are the typical values I've seen, you'll find others but they are not common.)
     
  18. maxpower097

    Thread Starter Well-Known Member

    Feb 20, 2009
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    10-4 Thanks for the tip. Shipping from digi is really reasonable. I think they want $2.41 for anything under half pound. So I may get a good selection of LED's and CAPS.
     
  19. Audioguru

    New Member

    Dec 20, 2007
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    My Samsung monitor still works like new. I guess the little Korean kids who built it are teenagers now. I wonder if they are paid more than one bowl of rice per day.
     
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