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51WH36 Mechanical Focus

Discussion in 'General TV Discussions Forum' started by Demon, Oct 5, 2003.

  1. Demon

    Demon
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    Having seen Nathan's results of mechanically focusing his 42pw23, I've just gone and done my 'new' 51wh36P...

    When the set arrived, it had a 'haze' over it... all white text seemed to be way too soft.. and it turned out to be condensation from being in the back of a soaking wet delivery van... (Damaged rear door had a 3" gap, and my TV Box was rained on for almost a day...

    But whilst annoyed with the haze (which lasted 2 days), and having my nose stuck against the screen inspecting the PQ, I soon noticed some imperfections in the focus... and comparing it to my Brothers same TV, it just didn't seem as good..

    The tell tale signs were
    1. Text had a double edge to it at times, and this made it hard to focus your eyes on. It didn't look massively out of focus, but you were aware there was somthing not quite right..
    2. Detail of hair and peoples faces never really stood out as much as my brothers (v.annoying)
    3. Convergence showed large areas that had a red haze to them
    4. The scanlines were not that visible..
    5. Some DVD's like Monsters INC did not blow my socks off as usual.

    So, having read about Nathans success, I thought I'd give it a go..
    For those that care, the procedure is identical.. the only real change is getting the screen off.. which involves the following steps..
    1. The main bottom panel just pulls off. Needs some persuasion, but its just big clips..
    2. The bronze strip under the screen is in two pieces, the right hand one has 3 screws holding it on.. remove these. The Left has 2 gold screws on the right hand side, and two black screws on the left.. remove these, then the whole power/control button panel just wiggles out easily, and can be left dangling on the long leads..
    3. The two lower silver side stantions are held on by 2 screws each.. remove these
    4. The screen section unscrews from behind, and the bottom, which is now exposed after removing both pieces of the bronze strip.
    5. Lifting the screen off is now easy...

    The usual Fishing line trick works beautifully.. what a great idea!! big thanks to whoever thought that one up..

    As for focusing, I followed the well documented method, using 2 empty black DVD cases to mask the other colours off.. although I did diverge on the test pattern used..

    I actually used sky.. the reason being that the bottom right on all the RPTV's I've seen always looks slightly blurred when you pop the channel info/time panel up in SKY, which you do a lot!!, and this is because the focus is harder to achieve in the bottom right.. and a compromise is reached between top left/middle and bottom right, but by using SKY, I think I managed to get a better setup then just using the test pattern!!!... (I just used the Channel Guide showing 'all channels' which is almost 100% text on the screen, with text on the top left/bottom right)

    It is important to electrostatically focus the colour you are working on first, as this will then reveal the scan lines more clearly, which then makes mechanical focusing easier...

    The results are great.. I know at least that its as good as it can be setup.. and am very happy with the results..

    the main improvements are
    1. The increase in detail was amazing.. I can see the scan lines very easily now, which makes the internal de-interlacer a worthwhile addition
    2. There is a more even focus when using SKY Menus/Film Credits, etc..
    3. The whites look much more contained and pure..
    4. The detail in films like Monsters Inc now blows you away... Stunning with a capital 'S'..

    I've seen the light once more, and will at some stage follow the masses, and line the inside of the set, but due to 'warranty' issues, I'll hang on for a little while..

    I will be cleaning the Lenses and mirror shortly.. I didn't have anything suitable in the house, so it'll have to be done later on.. but there was a significant amount of crap between the CRT and lenses.. there is a big flake on the green crt.. and I'm amazed how I can't really see any big effect on the picture...

    Many thanks to Nathan, and all the usual Toshiba RPTV tweak sites.. the mere fact that there is the indepth information and ability to tweak these Toshiba sets is one of the reasons I bought it...
     
  2. big brian

    big brian
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    demon I got one of these tvs 10 days ago and mine is as you describe, dont want to mess around in case I invaladate my warranty. Iam new to this so I just wanted to know what your sky picture was like, mine seems to be crap on some channels, ordered thor scart hoping to improve! picture.

    is your picture inline, mine tilts one side.
     
  3. Demon

    Demon
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    Things like the 'tilt', etc can usually be easily sorted out with the service level convergence.. you start with just a 'green' grid, and move this around until the geometry is spot on, all vertical and horizontal lines being 'true'... then you just converge the red and the blue to this...

    I do think my set was an exception, rather then a rule, every other set I, and people I know, have owned have always been in pretty good focus, its always been the convergence that is to blame, and that is easy to adjust, no need to open the set up..

    The best way to check is to use the service level convergence.. which does mean putting the set into service mode... this is reasonably a safe thing to do providing you do not adjust any of the 'data' that is displayed on screen, the convergence menu and procedure are all bullet proof, as there is no 'data' invloved, just moving a cursor around, and adjusting the red,green and blue..
    Anyway for focus check.. you can turn on R,G and B seperately.. with mine, when all three are on (the grid is white), over a large proportion of the grid, I had a red tinge on all sides of the lines... and if you individually look at the red and green grids, the red on mine looked very hazy indeed... especially when compared to my brothers... in fact we put each set into pic mode 2, and then I measured the 'width and height' of each colour's grid lines in the middle, and each corner, and compared, my red and green where 2-3mm wider then my brothers.. which showed how out of focus it was.. if you are prepared to get the service level convergence up, I can post these numbers so you have a rough guide...


    But it can manifest itself in other ways.. I would start with the convergence, and move on from their..
     
  4. big brian

    big brian
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    thanks for that, how is your picture with sky. please post numbers I am totally new to all this not much of a tec head.

    thanks
     
  5. Demon

    Demon
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    SKY is generally very good.. some of the lower bitrate channels, and older material can look a bit bitty and blocky, but thats the material, not the TV... mainstream stuff is good though, and occasionally you get really excellent detail that stands out a mile..

    I am going to tweak the focus even further this afternoon(I didn't spot it is slightly soft in the top right corner), and gather some pictures while I',m at it for anyone that fancies doing it to theirs... I'll also measure the width of the Red,Green and Blue grids in the centre and all corners.. so you can compare...

    Maybe some screen shots would help??? I'll see how good I can get a photo... TV's are hard to photograph sometimes..
     
  6. nathan_silly

    nathan_silly
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    Demon- don't bother spending too much time doing optical focus, as the electronic focus needs to be done before.

    Look directly into the green CRT (turn contrast way down to decrease eye strain) and twiddle the electronic green focus pot behind the speaker grille. Don't touch screen VR (think DRV or CUT adjustment).. you want equal horizontol & vertical thickness of the Green grid.

    Do the same for Blue & Red. THEN do optical focus.
     
  7. acucobol

    acucobol
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    Some photographs would be great.
     
  8. Demon

    Demon
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    Nathan... cheers... I did that first... I used the revealing of raster lines to give that perfect electrical focus.. this then makes the mechanical easier, as you can then look for the raster lines as 'proof' of perfect focus...

    I will do some photo's tomorrow.... as I want to 'clean' the lenses and mirror (so will be removing the screen yet again!!!), the amount of dust 'n' crap is unbelievable... there are chunks of crud on under the lenses... I am hoping compressed air will blow these out easily enough...

    I mentioned earlier, and will do mine, about measuring the service level grid lines width and height on all four corners and centre.. in pic mode 2.. for reference, I am not sure but this may be a rough comparison to see that others sets are in the same ball park??? I used this method to prove to me that the focus was a mile out on mine compared to my brothers...

    cheers once again for the advice..
     
  9. Loada

    Loada
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    Nathan/Demon,

    Have you two guys thought about producing some sort of "Ultimate guide to the WH36" complete with pictures. I'm thinking of getting a 42WH36 and I would definitely find use for such a guide. By the looks, of various replies to each of your recent posts a lot of others would also be interested.

    Just a thought...

    (unless the stuff is already out there on the 'net?)
     
  10. nathan_silly

    nathan_silly
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    I guess my SVM disable/RP lining & electrical/mechanial focus tips could be made a sticky (maybe in a CRT RP section?)

    The tips are already on the net (do a google search)
     

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