Page 1 of DVD picture distortion on 4:3 TVs. **TOSHIBA SERVICE SETTINGS ADDED**

maybe this is a stupid question but when i watch films on my crappy TV, the picture often appears bent at the extreme corners. this is especially noticeable with tall straight objects on the screen.
i`m assuming this is because i don`t have a flat widescreen TV and am unable to properly enjoy the delights of widescreen or 16:9.
i am sure someone out there has the technical knowhow.
cheers
kozza.

This item was edited on Saturday, 26th April 2003, 11:07

You said it your self, crap telly buy a new one.


Bear.

This is a problem with the geometry on the set and it can usually be adjusted if you can access the service menu. Even very expensive sets can have this problem.

28" Toshiba widescreen, great in every other aspect but does bend the pic as you described in the corner extremes still. Is there a service menu that will allow me to get at this through the RC.
Cheers...F...

Also worth checking to see if you have more than one A/V setting as they can make a big difference.
hth
P.

This item was edited on Friday, 28th February 2003, 17:51

I`ve found that picture distortion on either 4:3 or 16.9 sets often seems to be determined by the colours. If it`s white it bends in more at the edges.

SOmething else that happens, that really annoys me, is that if the volume is up high (as it often is with lower sound level DVDs), I get a really bad hum from the speakers when the screen is bright or white.

If you need to get into the service menu on your Tosh, follow these instructions;

Open the flap on the front of the tv with the volume up/down etc. Now take the remote, (the tv should be on by the way), and press and hold the mute button - now press the `menu` button on the front of the tv. You should see an `s` pop up in the top right hand corner of the screen, with a load of values in the top left. Hold the `call` button and press the menu button on the tv again and the s will turn to a `d`. This enables the designer menu, which allows you to tweak the individual widescreen modes rather than all of them at once.

As per usual, DON`T mess about without writing down all the values first as you will cock up your picture.

Go through each picture mode, using a THX optimizer with it`s grid option helps here. The main settings in the designer menu you need are;

(Settings are in the top left corner - i`ve described what they do here)

Use the channel up/down to cycel through each setting and the volume up/down to change each value. Press `exit` on the remote when you`re happy with the setting and switch off the power at the tv for 20seconds before switching on to do the next setting, (eg, if you`ve done 4;3 first, follow last instruction then go onto super live etc..)

HPOS - Alters the horizontal left/right position of the image.

HIT - BE CAREFUL HERE! As you adjust you will see the top and bottom of the screen stretching, you may only need a few presses to make this right.

WID - Suffering from a bit of overscan? Alter the overall width of the picture here. If you DVD has a zoom function, do it so it goes to the mode where the screen is zoomed out with a black windowbox around the image. This will give you a good indication of how much info is being overscanned by the picture tube.

TRAP - Imagine the picture is on a pivot that is attached to the screen horizontally through the centre. As you adjust you will see the screen tip backwards or forwards, (i.e the top of the image will move further as the bottom moves closer etc). This can be useful if the mate bars in 4;3 and 14;9 are a little `slopey`. That is, start out thicker at the top and thinner towards the bottom of the screen.

PARA - Very similar to the WID setting, but adds as a fine tune adjustment to the WID setting, Set the wide adjustment first then see if you need to use this.

CSAW - This adjusts any curved line issues. As you adjust you will see the top and bottom of the screen sway left and right. Again be careful as it can be very tricky to get right. Doing it wrong can mean stuff that scrolls up the screen will follow a wonky path up or down. Watch the end credits of a DVD to see if you have any problems.

VPOS - Adjusts the vertical position of the whole image.

CNR - Adjusts the top and bottom corners of the screen simultaneously. This one should iron out any problems at screen edges.

TCNR - Adjusts the top corners only - very handy if your geometry is screwed up top

BCNR - Opposite of above.

VLIN - Allows you to correct any iffy screen `bowing` at the edges - but is very tricky to get right! If you`re not sure what you`re doing, leave this well and truly alone.

Also, if you are feeling VERY brave, (disclaimer, wear rubber soles and have some supervision!), you can alter the focus and brightness of the tube if it is bloomy or if your screen has `clamp` problems. Clamping is my term for when the screen becomes bigger when any bright image appears, only to go back to normal when the image is normal. You`ll be able to notice with strobe effects, as it gets brighter the screen will overscan, then go back to normal when normality is restored. Now, PLEASE be careful here - tv engineers are trained don`t forget!

Take off the back panel from your tv while it is UNPLUGGED at the mains. Now as you look at the back, there will be three little rotary adjustment controls in the bottom left corner of the circuit board. I am going by recent Tosh flat screen sets here, so this may not apply to yours, but the flat models are the ones which have had the most problems. One will be the focus adjustment, it will say on it but if not it is usually the middle one. Now switch on the tv, and put on a DVD and select the end credits from the chapter index. Pause when the credits stretch the width of the screen. Now look across the image and check whether the focus of the font is clearly visible and redable from your normal viewing distance. If it is blurred at the edges, then adjust the control very slightly and you will see the image becoming sharper across the screen. It`s simple and can be done quite quickly. Once your happy, (try few discs to get the best result for you), leave it. Now, the brightness control acts as a `default` brightness setting, so when you set the brightness in the tv`s adjustment menus to 50% or 0, this control affects that. Some tv`s leave the factory with this set too high, and as such you may not be able to get the right image when calibrating the tv. Again, adjust this very slowly using the combination of a THX optimode, (if you don`t have one, borrow one) and the on screen menu`s of the tv. Once you`re happy, you`ll need to adjust the contrast in the on screen menu to compensate. Switch the tv off, put the rear panel back on and leave the tv for 15 minutes. After the time is up, switch on, and the tv will degauss and to all intents and purposes, should look perfect in every mode! The only one which you may have trouble with is 14;9, but that can be rare :-)

Once again, be careful! I managed to get the piccy on my Tosh within a millimeter of perfection, you should too unless it is absolutely all over the place from the factory, (i`ve seen some horrendous ones!).

Hope this helps!

Westy

Site Technical Help Editor and Moderator

Home Cinema Editor - Area450