cannot adjust horizontal shift on rgb crt tv

[filevans]

THello all
I have a 1996 panasonic 4:3 ratio crt tv which i use for all my consoles

But the image is a few mm too far to the right. Ive entered service mode but horizontal shift wont do a thing on rgb scart. It only shifts the picture on composite or svideo input. I tried to change it anyway and save the values and turn the tv off and on again but picture has not moved on rgb. Only has moved for composite etc

Is there something i could do to adjust it inside?

Thank you very much

[Skips]

THello all
I have a 1996 panasonic 4:3 ratio crt tv which i use for all my consoles

But the image is a few mm too far to the right. Ive entered service mode but horizontal shift wont do a thing on rgb scart. It only shifts the picture on composite or svideo input. I tried to change it anyway and save the values and turn the tv off and on again but picture has not moved on rgb. Only has moved for composite etc

Is there something i could do to adjust it inside?

Thank you very much

You are not running a sync stripper anywhere in your setup are you? I have noticed that some Panasonic monitors shift the image to the right by a full inch when using one. I would not be surprised if the same is true for their TV's as well.

[Xyga]

Dunno if it's the case here but some crt tv's despite being equipped with a digital chassis, still use a few potentiometers for things like horizontal position, pin cushion or something like that.
I have a Thomson with an ITC008 chassis working like that, the service menu is accessible but is not complete, you still have to open the case and fiddle with pots...

[filevans]

Ok but as i said, it is moving the screen for composite and svideo and uhf. So horizontal position is working. Just doesnt affect the rgb input.
There must be something i can do inside but i dont know what

[Xyga]

Yes I read that but the controls could be different and separate for different signal types. This is not uncommon.

The method for horizontally shifting RGB should be described in the official service manual... I say should because I've had a hard time finding it for my Thomson, actually got it from a random forum post while googling about the issue...

[filevans]

Yes ive got the service manual but couldnt find anything in it about horizontal screen adjust of hardware type, it is panasonic tx-28md3, might you be able to look if you can see anything mate. Thanks a lot for your help

[neorichieb1971]

In my experience you just adjust it in another mode and keep coming back to RGB until its right.

[filevans]

In my experience you just adjust it in another mode and keep coming back to RGB until its right.

I'd already said previously it doesn't

[Xyga]

Couldn't find anything on the service manual clearly stating 'this adjusts the horizontal position', but there are obviously a number of potentiometers that could be 'it'.

On the CONTROL AND POWER BLOCK DIAGRAM you can see parts called 'IC701 HORIZ OUTPUT' and IC451 VERTICAL OUTPUT'.
PIN top and bottom on the 28MD are parts TPD8E639 & TPD8E640. Can't locate those on the full diagrams, it's too small/complex to read just like that.
You'll have to figure it out...

It's frustrating to read 'H-POS' listed in the service menu's alignment settings though, it' the same on my thomson but in my case what's missing in the menu is horizontal amplitude/size.

Well good luck, it's not certain of course, but your only option light be to open that tv and find that potentiometer by trial and error.

[filevans]

thanks a lot for your help mate. I am going to try and have a go at it.
the problem is as it's on the power block I am a bit scared as some components there are 30,000 volts

[Xyga]

The insides of a CRT scare me too lol. Plus you can really mess up things depending on what you touch.

Absolutely use insulated tools and wear thick rubber gloves if you can, make sure there's nothing in your way like a chair, shirt sleeves, etc.

Oh and of course you'll need a mirror.

[MKL]

The only pot is the b+ one and you don't want to touch that. There are no other pots, this is a fully digital chassis. The only components that can affect the picture horizontally are the coils L552 (linearity) and L554 (adjustable but hard and definitely not by a noob) but that's not the way to adjust the picture. It's really only done via the service mode and if it doesn't work for you then something is bugged (perhaps the eprom).

[neorichieb1971]

It really surprises me that in no part of the videogame fraternity did any of the hardware developers think to include a horizontal/vertical shift/stretch in the console hardware. I mean, how hard could it be to implement?