AV mod problem

[ApolloBoy]

I performed the S-video mod as outlined on the 5200 FAQ a while ago, and while it works great it's not perfect. I seem to be getting gray lines that scroll vertically over the screen, and I'm thinking it has something to do with the fact that I left out a resistor going to the chroma output. I can't tell if this does it over S-video or not, since I haven't installed an S-video jack yet.

Edited October 15, 2008 by ApolloBoy

[Prodos8]

Try hooking up only the luma portion (you should get a crystal clear b&w) on composite or s-video and that will let you know if its something with the chroma or not. I've performed the mod on my own and put a pot on the chroma line that's basically set to 0 resistance as I get a much cleaner picture, without a fringe effect on all the pixels, that way. I can attest that the mod worked great for me on CRT TVs (not so good on LCDs), so you might wanna re-check the luma portion of the circuit as I beleive that's where your problem probably is. Also, unlike the description in the FAQ, I tapped the chroma signal from the right-most resistor on that row on my install.

 

Good luck with it!

[phonedork]

Try hooking up only the luma portion (you should get a crystal clear b&w) on composite or s-video and that will let you know if its something with the chroma or not. I've performed the mod on my own and put a pot on the chroma line that's basically set to 0 resistance as I get a much cleaner picture, without a fringe effect on all the pixels, that way. I can attest that the mod worked great for me on CRT TVs (not so good on LCDs), so you might wanna re-check the luma portion of the circuit as I beleive that's where your problem probably is. Also, unlike the description in the FAQ, I tapped the chroma signal from the right-most resistor on that row on my install.

 

Good luck with it!

 

 

Can you post a pic??

[Prodos8]

Can you post a pic??

Pic of what?

 

I can't really take a pic of the mod itself unless I remove the RF shield, which is a real pita. As far as the performance on LCD tv's I get a about thirty or so vertical lines at regular intervals across the screen.

[phonedork]

Can you post a pic??

Pic of what?

 

I can't really take a pic of the mod itself unless I remove the RF shield, which is a real pita. As far as the performance on LCD tv's I get a about thirty or so vertical lines at regular intervals across the screen.

 

 

I have a modified S-video and Composite 4 port Atari 5200 with a power modification as well to avoid that power box thingy. Anyway this is the 8bit domain mod. The AV is clear and nice looking without any vertical lines what so ever, but the S-video is a bit clearer and appears to have no color bleed, but has vertical lines through any solid color other then black or white. I believe I miss read what you said about adding a pot on your mod to add resistance to get rid of the lines in s-video. You still seem to get the vertical lines. I thought maybe adding a pot somewhere on my mod would fix my lines. For now I just use the AV since it just looks better then the s-video.

[Prodos8]

Can you post a pic??

Pic of what?

 

I can't really take a pic of the mod itself unless I remove the RF shield, which is a real pita. As far as the performance on LCD tv's I get a about thirty or so vertical lines at regular intervals across the screen.

 

 

I have a modified S-video and Composite 4 port Atari 5200 with a power modification as well to avoid that power box thingy. Anyway this is the 8bit domain mod. The AV is clear and nice looking without any vertical lines what so ever, but the S-video is a bit clearer and appears to have no color bleed, but has vertical lines through any solid color other then black or white. I believe I miss read what you said about adding a pot on your mod to add resistance to get rid of the lines in s-video. You still seem to get the vertical lines. I thought maybe adding a pot somewhere on my mod would fix my lines. For now I just use the AV since it just looks better then the s-video.

In my experience I get the vertical lines on LCDs using composite or s-video. I'm looking at adding a FMS6400 video filter chip, to my mod, that longhorn was experimenting with. His new mod is basically the faq mod with the addition of that chip that he says elimates those pesky lines on LCD displays.

[phonedork]

Can you post a pic??

Pic of what?

 

I can't really take a pic of the mod itself unless I remove the RF shield, which is a real pita. As far as the performance on LCD tv's I get a about thirty or so vertical lines at regular intervals across the screen.

 

 

I have a modified S-video and Composite 4 port Atari 5200 with a power modification as well to avoid that power box thingy. Anyway this is the 8bit domain mod. The AV is clear and nice looking without any vertical lines what so ever, but the S-video is a bit clearer and appears to have no color bleed, but has vertical lines through any solid color other then black or white. I believe I miss read what you said about adding a pot on your mod to add resistance to get rid of the lines in s-video. You still seem to get the vertical lines. I thought maybe adding a pot somewhere on my mod would fix my lines. For now I just use the AV since it just looks better then the s-video.

In my experience I get the vertical lines on LCDs using composite or s-video. I'm looking at adding a FMS6400 video filter chip, to my mod, that longhorn was experimenting with. His new mod is basically the faq mod with the addition of that chip that he says elimates those pesky lines on LCD displays.

 

I actually went to Target and bought a CRT television since there cheap and dedicated it to my vintage systems. When I run Coleco, Atari 7800, and 5200 s-video on a regular CRT television I get the same thing. Vertical lines even on a CRT. But AV seems to be fine even on a flat screen. I actaully thought that a CRT would fix this and it did not.

[Prodos8]

I actually went to Target and bought a CRT television since there cheap and dedicated it to my vintage systems. When I run Coleco, Atari 7800, and 5200 s-video on a regular CRT television I get the same thing. Vertical lines even on a CRT. But AV seems to be fine even on a flat screen. I actaully thought that a CRT would fix this and it did not.

Well all I can say is the faq mod works great on a CRT TV. Don't really know about the 8-bit domain mod.