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PJ arrives today - how to check for dead pixels?

Discussion in 'Projectors, Screens & Video Processors' started by rjs1974, Jan 13, 2003.

  1. rjs1974

    rjs1974
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    I don't yet have a screen, so will be using a white wall in the short term, but clearly I want to check for dead/stuck pixels and return it asap if I have to, so how can I best check for them?

    Thanks guys.
     
  2. Underscore

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    I am fortunate enough to have a laptop for work. I just created a powerpoint presentation with five blank slides, each of a different colour - black, red, blue, green, white - and then used the PJ to project it. Any dead or stuck pixels should be easy to spot. Mine was defect free. :D

    HTH,

    _
     
  3. LV426

    LV426
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    Bad pixels can be bad in two ways (mainly):

    Always bright
    Always dark.

    Always dark ones are rarely visible in normal use, so forget about them.

    Always bright ones are visible in normal use.

    Put in a DVD and pause it on a plain black image - eg before the movie fades in at the very start, or after the titles at the very end.

    And look for any bright pinpricks (definite pinpricks, sharply focussed) on the 'screen'. These are bad (bright) pixels.
     
  4. rjs1974

    rjs1974
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    Can I connect my HS10 to a laptop to try the PowerPoint presentation thing, with the lead supplied in the box? Or do I need to buy another lead?

    Cheers!
     
  5. Underscore

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    You need a VGA cable - unless your laptop has a composite out - so you will probably need to beg, steal or borrow one of those. I was able to borrow one from work for an evening - there are usually some lying around in the IT systems area of most companies.

    HTH,

    _
     
  6. rjs1974

    rjs1974
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    I heard it does not, and am yet to unpack mine (until I get it home).

    If not, what is the optimum way for me to check for dodgy pixels tonight, on a white wall, using my DVD player and the supplied lead?

    Wholly black image?
     
  7. marcw

    marcw
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    How obvious would these dead pixels be? I've got a HS10, bought from Hi Spek on Saturday, who don't offer a dead pixel check... I've set my laptop up as per this thread - with a Powerpoint presentation - five slides, black, white, red, green, blue. I've run the laptop out through it's internal S-Video out to the PJ and I couldn't spot anything obvious on my 6ft wide screen... Do dead pixels stand out easily or am I perhaps not being critical enough?
     
  8. Smurfin

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    Unless Hi-Spek have a good returns policy on projectors with dead pixels then don't bother looking for them!

    I gave my projector a fairly critical going over, but I bought it from a retailer who would exchange if I wasn't happy.

    So check this and make sure!!!!!
     
  9. marcw

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    Sod's law. Gave it a quick once over and found nothing, went over to switch my sub on earlier and spotted a bright red dot on the left hand side while I wasn't even really looking... Not sure if it was there before or not, do they ever disappear?

    Secondly, got a green "stripe" about 1 or 2 pixels wide down the extreme left of the picture, is that normal too?

    Should I just live with it I wonder?
     
  10. rjs1974

    rjs1974
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    As for the green stripe, I have it on probably all edges of mine, I believe it is just totally normal misconvergence at the extremities, and as you say, is about 1-2 pixels wide.

    Wholly normal, as far as I know. My guess is you can't see it unless you are within 3-4 feet?

    On the issue of pixels, to be honest, I am as pedantic as they come, but I have decided to be philosophical about dead/stuck pixels. Mine has a few, but to be fair you can only see them on the grey memory stick page, and one that you can see when the whole screen is black and I stand within 3 feet. Since I sit 12 ft away I am being over picky.

    Truth is, I truly believe if you look for iffy pixels on any LCD device exhaustively enough, you WILL find them. I could not find a single one on the blue background, but if you switch to the grey, I suspect you will find several green pixels. My advice: don't go looking, just enjoy it and appreciate that it IS a cracking PJ!

    Good luck!
     
  11. marcw

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    Agreed. I reckon there are others present on the panels, but this is a bright red dot visible against black. If it were only present on specific colours it would be less visible dependent on the shade of that colour, but cos it's black it's a bit noticeable...

    Think I'm going to take it back to Hi Spek. They have no more in stock, so I'll get a refund and buy from NexNix instead.
     
  12. alanesmith

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    have i got a bad pixel ? the picture is sharp enough to see the grid pattern up close, but the red spot appears blurred, not as you say a sharp pin prick

    Alan
     
  13. LV426

    LV426
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    Probably not a bad pixel, then.

    You don't say whether it is the same size (more or less) as a single pixel (ie gridspace) or if it's a lot larger and very soft.

    If it is the latter it may be dust in the optics.
     

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