Help with Geometry on Toshiba 57HDX82

[EVT]

Hi guys,

After owning by Tosh 57 HDX82 for almost 6 years i decided to try and address overscan through the service menu. I read an online tutorial where the individual noted it was easy to fix the geometry by eye once you had set your overscan; unfortunately I found this was not the case and I'm unable to get it back to a state that I'm happy with. I have tried the string method but I kept having the horizontal strings drop.

I can't seem to locate a geometry grid for this TV; if any knows of where I can get a grid or has another practical suggestion to fix this it would be greatly appreciated.

Thanks.

[57]

Since the geometry grid will be for the "factory" settings and will not really line up with your new (lower overscan) settings, you may wish to retry the string method, but pull the strings nice and tight so that they don't droop, perhaps wrapping them around to the back of the TV and taping them there.

You should be able to do a simple calculation so that the distance between the grids is even and that the strings are put in the correct location.

[EVT]

To be honest, I think that I'd rather have good geometry with 5 - 6% overscan so I'd be willing to go back to the factory settings. However, I guess if a geometry grid cannot be found at this point then I'll have to go back to the strings.

57,

You noted that "You should be able to do a simple calculation so that the distance between the grids is even and that the strings are put in the correct location. "

I'm not sure how I would do this; are you saying that the distance should be the same? Does this apply both horizontally and vertically? So in other words, are you suggesting that I measure for example the height and then divide it by the number of horizontal lines to come up with the spacing?

[57]

I'm suggesting that you measure the distance between the outer-most lines (or pair of lines), divide by the number of lines (actually the number of spaces) to come up with the average spacing. I'm not sure if the spacing will be the same horizontally and vertically (if the cells are square). You can compare this calculation with the rough spacing that you've got now before doing the strings. This will ensure equal spacing and straight lines.

[EVT]

I guess I can try that if a grid isn't available but my preference would be to get a grid to do it. Looking at the grid it's hard for me to tell whether the boxes should all be the same size which is another reason I would prefer to just get a hold of a grid and live with a little extra overscan.

[57]

In your search, I believe this is sometimes called a "screen overlay" - perhaps do a search using that or similar terms. I believe the boxes inside the outer-most lines (or pair of lines) should be the same size, I'm just not positive if they're rectangles or squares. A service manual may also contain the spacing information - it does on Hitachis, not sure about Toshibas.

Edit: Sometimes there are two outside lines that are fairly close together - say 1" apart, and then there are the rest of the lines inside those two that are identically spaced. This should be pretty evident from the pattern.

If you do get a service manual or overlay, you should be able to compensate for the difference in overscan (5-6% to 2% say) by multiplying the spacing by 1.03 to 1.04?

[EVT]

Thanks 57, I guess if I don't find a screen overlay I can give what you've suggested a shot.

If anyone else does have any idea where to get a screen overlay it would be greatly appreciated.

[EVT]

So I take it that there isn't anyone who is aware of where I can get a screen overlay?

[Alan Bealby]

There used to be PDF files of the overlay for some of the Toshiba rear-view projection TV's online. I downloaded and printed the 4 grid overlays for my Tohsiba 65X81 (?). My memory isn't that good so I'll have to find something to give me more specifics. If I do find something I'll post it.

[Alan Bealby]

Here's a link to the site from which I started my successful search for a convergence grid for my Toshiba TV. Note that it looks the same as what it did 5 or 6 years ago so that the links may no longer be valid.

http://www.keohi.com/keohihdtv/brand...ence_grid.html

And edited to add a link to a more generic Toshiba tips page.

http://www.keohi.com/keohihdtv/brand...hiba_tips.html

I do recall that it was John Golitsis that prepared the pdf files that I was able to download for my Toshiba TW65X81 model. I had to go to a commercial printing company to get them printed and they had problems getting the size to come out correctly. The acetate is expensive printing material. It cost me almost $100 for the 4 grids I wanted.