While I was developing my replacement Atari PSU I noticed the video quality improved immensely. However, I still saw some "ghosting" on the display which baffled me for a few hours. While ghosting can be other factors, such as bad video cable, or a bad LCD TV, for me the problem was on the Atari itself.

On the left is the image before my fix, and on the right is after my fix. The left image shows ghosting to the right of the Atari Fuji and at the ends of the black box lines. While the ghosting is faint it can still be seen clearly compared to the image on the right. Thankfully the fix is a easy one..

NOTE - This mod was to fix RGB/scart issues and has not been tested with RF or Composite video signals.

Near the top left of the simms there is a yellow capacitor (C411) which needs more capacitance across it. The odd-ish thing is, R544 is actually a 8V regulator feed from the 12V rail. Normally I would have expected good regulation there, and it is, but its still not good enough to solve the video problems.

The results are...

1uF ceramic doesn't fully solve the ghosting problem.

10uF electrolytic probably 95% solves the problem.

47uF seems to work best, may improve a couple % with the 1uF in addition.

So a 47uF capacitor with the possible addition of a 1uF ceramic seems to fix this issue. Larger values than 47uF can be used, but I would not recommend going below 47uF. Like I keep saying over and over in other pages on my site, you NEED low ESR capacitors otherwise "any old capacitor" will not work! Look towards Panasonic FR range of capacitors. I generally have a stock of all sorts of values of capacitors in my store if anyone needs some.

That's it! Enjoy your ghost free display :)

Some example part numbers :

http://uk.farnell.com/panasonic-electronic-components/eca1cm470/cap-alu-elec-47uf-16v-rad/dp/9693572 ( ECA-1CM470 )

http://uk.farnell.com/multicomp/mcmlr50v105my5v/cap-cer-y5v-1uf-50v-rad/dp/2112910 ( MCMLR50V105MY5V )

Another couple of images of ghosting issues (and fixed ) on a STE I was servicing today..

I had a MSTE in for repair so I looked into solving the ghosting issue. It was only slight on this machine, so capturing a image proved difficult. However with soldering a low ESR 10uF capacitor across C506 as shown in the above image removed what little ghosting I saw.

If anyone can verify this and take images on their own MSTE then it would help.

The vertical interference pattern's characteristics can vary significantly, influenced by the specific combination of the TV and Atari model. This interference pattern may exhibit either a stationary nature or present the classic "dot crawl" issues. Moreover, its intensity can fluctuate, showing improvements or worsening based on the temperature of both the machine and the TV during operation.

The Atari machines themselves contribute significantly to interference, presenting a challenging issue to address. An upgrade option, the Video DAC upgrade for STFM machines, proves highly effective in minimizing interference and delivering a cleaner, sharper image.

It's essential to recognize that the RGB outputs on the Atari often include capacitors to mitigate interference, though not consistently across models. For instance, the STE does not have them fitted. Typically, these capacitors range from 22pF to 100pF, connected to each RGB signal to GND. While effective in alleviating interference, higher capacitor values unfortunately introduce some blurring to the image.

Above the 3 green circles denote where the 3 47pF capacitors solder to. The yellow circle denotes a GND point for the 3 capacitors.