General Category > Technical Support

Adjusting the image in the original screen.

(1/11) > >>

I know that lately I am bothering you a bit too much with all my hardware "problems", sorry, this is what happens when you buy stuff from e-bay from time to time  :picard2: Luckily, I did not experience any serious issues, just minor things that needed to be adjusted.

Now is time for the screen. I received it a few days ago along with a working 464 Plus and I am actually very happy with it. I was carefully cleaning the unit and it works very well. Sound is good, color is bright and image is crisp. However, there is a BUT, and in this case is the geometry of the image. It turns out that the image is apparently slightly rotated counterclockwise. However, if you check more carefully, the "rotation" mostly affects the top right corner. So, some of the electrons are actually traveling a bit longer than they should. I have a big speaker next to the screen, and the first thing I tried was to remove it, but it did not help. Now I remember that I also have a subwoofer below table that I did not touch, I will try this today. But, in any case, assuming that it is the screen itself, could you tell me if there is a proper way to adjust the geometry a little bit? or, in case I need to check something in particular inside could you point me to it? I have quite a lot of experience with audio amplifiers, but not with CRTs, I never liked to mess with them so much for obvious reasons  :D

This morning I took a picture for you to see. If you check carefully, the image is a bit bent toward the upper right corner (sorry for all the stuff that appears around)


Any help be much appreciated!!

I'm not sure if there is anything in the monitor to adjust that (I think not, but if there is, there's a good change it should be indicated in the service manual). While cleaning it up, did you moved somehow the internal speakers? But from the picture, I think it is Prophet's nanosuit trying to absorb the electron beam :)

Hahahaha, no, I did not move the magnets. Maybe it is actually Prophet, who knows! Checking the service manual of the other models of Amstrad screens I found that there are some knobs inside that could be probably used, but I never tried to adjust anything like that. That is why I am curious to see is somebody did it in before  :)

A little "rule of thumb" I learnt back when I was fixing TVs regularly: Only symetrical problems (such as pin-cushioning) can be fixed with adjustments, if it's non-symetrical it's usually some component that's failing or has failed.
In your case it could be a convergence problem (colours not lining up properly) or there's a similar issue where the top left border gets slightly dragged to the left (there's a name for this, which I can't remember at the moment). Both of these issues can be due to several things, but in a device this old, my first bet would be capacitors dried out and dying.

If you can display a squared grid on the screen and post a picture of that, it would be easier to analyse the problem.


Thank you Bryce! I will display the square grid then  :) Replacing the capacitors should not be more difficult than usual if this is necessary. I will just try not to end like a fried chicken  :picard: . One thing I noticed is that there is not convergence problem as such, all the colors are displayed very properly (at least judging by eye), is just the slight deformation.


[0] Message Index

[#] Next page

Go to full version
Powered by SMFPacks Media Embedder
Powered by SMFPacks Alerts Pro Mod
Powered by SMFPacks Mentions Pro Mod