Screen pushed to the left in rgb mode..

[Darklegion]

Well after finally repairing my tv to the point where everything is good(had to change a lot of parts and repair alot of cold solder joints),and adding a scart connector for the rgb video that everyone was raving about,I was very pleased with the result...except for that small problem that most people with a rgb tv has to put up with,which is the screen seems to get pushed an inch or so to the left leaving an ugly black border as the one taint on an otherwise perfect screen.I've only tested this on a dreamcast,but I know it happens on a saturn and probably most of other consoles too.Has anyone tried to work this out? I figure I could wire up an external pot to the control that controls the screen position,but that could be a pain,and I don't wanna risk losing alignment.Maybe an IC that could do it? If worse comes to worse I might just adjust it so its perfect for rgb mode and bugger the rest since I get a crappy free-to-air reception and I have no need for composite any more.Any way if anyone has done this before or knows of someone/somewhere who has that would be nice

Thanks
DL

[NFG]

It's a result of sloppy factory calibration, there's not much you can do about it.  Your TV is programmed to adjust the video settings based on the input, and anything not quite standard or up to what the TV expects will result in Weird Things.

[benzaldehyde]

Are you feeding the monitor a CVBS signal for sync? Or, are you using a LM1881 seperation circuit to get the sync signal. I read somewhere that the sync separation offsets the video timing a little, resulting in a shift toward the left of the entire picture. Mind you, I have no comprehension of "video timing," but I have observed the effect when switching between the PSX (needs LM1881) and Saturn (doesn't) on my monitor. Also, I would add the horizontal adjustment. You might need it later . Good luck!

[Guest]

Well i tried moving the h-phaser pot,didn't allow much variation at all though,the screen moved about 2mm to right and then it wouldn't turn any further..
I'm using dreamcasts horizontal sync tied with the vertical sync because composite sync wasn't working before...this could possibly be it.It does seem to be a common problem though,probably not much I can do about it.On a similar note,I also seem to be getting clear horizontal lines rolling up and down the screen...really noticable on white backgrounds..i.e psx and dreamcast loading screens.Also makes textures flicker because of the lines messing up the picture,which is a bit like the diagonal lines you often get on composite mode only worse.I think it could be because i replaced the bypass capacitor on the composite video line with a non inductive mkt,and the original was a inductive polyester...same values otherwise though and these are  both polyester..does anyone think this is the sort of effect you would get from a failing/wrong bypass capacitor? Guess i'll take another look tommorrow,although this is starting to get annoying.

[benzaldehyde]

The DC's C sync signal is pretty nasty; to get a good sync you'd need to run it through a LM1881. I'm not sure how clean a sync you would get from tying H and V sync together. I think you would have to run it through a logic gate or two to get a good sync. I'll look around; I think I have a schematic somewhere. You're rolling picture is probably from EM interference due to a lack of shielding in your cables. It seems to be worse if the system runs at a high resolution (i.e. DC, sometimes N64 or PSX). I don't know if it has anything to do with the bypass filter; I take my CVBS from the system without filtering and use it for sync, and my picture looks pretty clear. You may want to look into upgrading those cables. (I know it sounds bad, but it isn't. I just finished replacing all of mine with shielded brands. ). Hope this helps you out.

Speaking of which, anyone know where I could find a shielded SNES/N64 RGB cable? Everytime I purchase one it's always unshielded. Do they even exist?

[Guest_Benzaldehyde]

Ummm... your...

<You are... rolling picture!>

:lol:  

[Guest]

Nah i'm talking about the bypass filter inside the tv...nothing to do with the cables whatsoever as i've tryed with regular rca cables through scart to rca converter and straight through the regular rca in,as well as a rgb cable obviously......using the lm1881 might clean up the border problem though...I have the chip but suprisingly couldn't find any 0.1 uf capacitor laying around in my junk equipment so i'll have to pick some up later this week.

As for your second post...have you been knocking back a few...refreshments?

(simpsons quote)  

[davidleeroth]

Just had a thought about magnetics and tvs.
In theory, a magnetic field near the cathode-ray tube will result in a shift
of trajectory for particles shooting on the screen.

So, if a suitable magnetic field is applied, the picture will shift to the appropriate direction.
If the field is far enough from the screen no color errors should occur either.

Haven't tried this one in practise yet but in theory it should work.

[NFG]

You won't see a picture shift, what you'll see is a colour shift.  Yes, you can affect the electrons as they whiz through the tube, but the ones slamming into green phosphors are going to shift and slam into red or blue ones, resulting in discolouration, not image movement.  

It won't work, do NOT dry this!

[davidleeroth]

Too late Lawrence,
I tried it with my crap tv and yes, the picture shifts according to the magnet.
There was a  slight hint of discoloration on the very corner of the screen when the picture was pushed to the right about half a centimeter.

But, like Lawrence said, this is NOT a solution, it's just me being a stupid and ignorant f*** like I am.  

[NFG]

On the bright side when you muck about with magnets and TVs the image will usually go back to normal in a while.  No harm in experimenting.  =)

[Darklegion]

Well,my power cable for the tv shorted blowing most of the power supply area...so I can't help on this until I get all those parts replaced.I have an inkling that this was what was causing my lines problem though,so hopefully this will sort it out as well..

Yeah the auto-degaussing circuits usually fix magnetic problems right up,so don't worry too much about it.Let us know if you end up trying again and can get it work...be the guinea pig
I've heard that newer tvs with service menus have more range on their adjustments than tvs that just use pots,so you might have better luck there.Also some older tvs(back in the '80s) had full overscan adjustments so you could change the size as well as position....unfortunately my tv is right in the middle between new and old,lol.
This seems to be problem on pretty much all tvs though,probably the game consoles fault as much as the tv,possibly through the use of non-standard resolutions.Tvout will be good though,because you can adjust overscan and position through software,elimination this problem....someone with programming ability should look to fix this for game consoles too...I remember a utility for psx called import player light,which allowed screen position adjustments in game,don't remember how well it worked though but its worth a shot.I porbably won't bother modding it for rgb though as emulators are so good these days  

Thanks
DL

[Bikkuri!]

Darklegion, did you add an RGB input to a TV without RGB input? If you did, i just want to know how did you do that. That quite amaze me as for Japanese TV is hardly to get RGB input unless your TV is above 30" i assume.

[Darklegion]

Darklegion, did you add an RGB input to a TV without RGB input? If you did, i just want to know how did you do that. That quite amaze me as for Japanese TV is hardly to get RGB input unless your TV is above 30" i assume.

Yes,I did but since my tv is australian TV that uses a similar chassis to its european counterparts,all I had to do was solder a scart socket on,and that was that  A japanese tv wouldn't be using a european chassis though,so you're out of luck.There is anther way you can do it though(well a couple of ways) one is easier and seems to allow proper picture adjustments...its basically swapping a tv chassis with a cheap arcade monitor chassis(which takes rgb like a scart tv) but you won't be able to use it like a tv.The other way is to solder the rgb lines straight onto the neckboard or onto a via or IC on the mainboard that takes rgb(all TVS do at some point)....Be aware for all these methods that you should definately learn about safety before digging around in a tv or monitor,you could ever f*ck the tv up or more importantly you could be more in for a serious and possibly lethal shock if you do something wrong.Also for the second hack its not something that will work universally(and the first one too really),so you'll need to have at least a decent understanding of whats going on and how tvs work(or are prepared to learn)
Here's some links about this:
www.repairfaq.org - read the guides for working with TVs an particularly the saftey sections,it details how to discharge the crt and the filter caps and gives various info about what not to touch etc and info so you can understand better whats going on in there.
http://www.arcadecontrols.org/yabbse/index...y;threadid=5448 - a thread about swapping about swapping a tv chassis with an arcade monitor chassis
http://www.arcadecontrols.org/yabbse/index...;threadid=11458 - a thread about wiring in rgb directly to the neckboard

DL

[davidleeroth]

I've got a year old Sony and my trusty 80's trio: 14" Luxor tv, 28" Finlux monitor and Commodore 1084.
Only the 1084 has size and position adjustment.

I don't how the adjustments work technically but would it be possible to add these adjustments to my other screens  by tracing back the pots on 1084 and using that info?

Edit:

Why make life hard when there's Google. I found this:

http://members.accessus.net/~090/awh/sonyp....html?KeohiHDTV

Wohoo!    

[NFG]

Why make life hard when there's Google.

Words to live by.  You've reached wisdom early, my son.

[davidleeroth]

I reconfigured the Sony and I have to say the factory settings were horrible. The screen was pushed a full centimeter (a lot on a 14" screen) to left and bottom. And the picture was way too big.
Now I can see my score and the bastards shooting at me in Battle Garegga  

It's not all without problems however, PS2 picture is pushed to the right when the Saturn picture is just right. A lot of fiddling ahead...

I guess my 80's set doesn't have a service mode (even if they did, their remotes got broke like 10 years ago) so it would be nice to make adjustment pots for these.

[davidleeroth]

Darklegion:

You might wanna try different voltages on pin 8 on the SCART connector. When I was using the Service Menu on my Sony strange things happened when I connected a voltage to the pin: the horizontal centering value changed every time a voltage was applied, i.e. from 50 to 57 thus moving the picture to the right.
Dunno why, it just did. Might just be my tv.

[Darklegion]

I had no voltage on pin 8...didn't think it would be needed as I have manual switching AV and get autoswitching through pin 16(which gives a weird bloody picture when not switching to AV mode manually,i.e no sync at all) That could be it actually,but I can't test yet....don't really have any money to waste on this at the moment..

Thanks
DL