Killed color output on XEGS

[AtariSociety]

In my tinkering with my XEGS that has cartridge issues not always working proper, I seemed to have now killed color output from both my composite and RF TV port. 8-( I had removed my PC Board to tinker with the cartridge connector and when I put it all back together, I had no video at all. When I went back in noticed the cart insert bent one of the cart connector pins. I rebent that in to shape and now all works again but zippy on color. Only black and white.

 

So, I must of zapped something to do with color output. Anyone do this before and have advice on how to fix or my guess, I just killed the XEGS for good unless I give it to someone that is color blind. hehehe.

 

Thanks for the ear,

 

tj

 

* I could not find a way to change the title of my other XEGS cart thread so decided to make a new thread since this is another issue.

[dmlloyd]

There's a small trimmer potentiometer which adjusts the color output - try turning that. If you sprayed cleaner on it you may have inadvertently affected its resistance.

[AtariSociety]

There's a small trimmer potentiometer which adjusts the color output - try turning that. If you sprayed cleaner on it you may have inadvertently affected its resistance.

 

I opened the case again and I see, maybe a pot of some kind next to the cart port. Turning it left and right seems to make no different.

 

Bummer. Not sure if that was the pot anyway but wonder what position it should be in anyway.

 

TJ

Edited June 9, 2010 by macsociety

[Rybags]

There's no set position, that's why it's there, because every machine is slightly different, and it gets adjusted at the factory to meet the reference specifications.

[Divya16]

There's a small trimmer potentiometer which adjusts the color output - try turning that. If you sprayed cleaner on it you may have inadvertently affected its resistance.

 

I opened the case again and I see, maybe a pot of some kind next to the cart port. Turning it left and right seems to make no different.

 

Bummer. Not sure if that was the pot anyway but wonder what position it should be in anyway.

 

TJ

 

It's like a Mac SE/30 now. I wonder if that has a color pot that nobody knew about.

[AtariSociety]

There's a small trimmer potentiometer which adjusts the color output - try turning that. If you sprayed cleaner on it you may have inadvertently affected its resistance.

 

Does not seem there is much to do with these pots. I tried adjusting some more back and forth while the system was running but I get no glimpse of any colors. Are there any other components that deal with color on or off or is this pot it? Maybe I could replace the pot? Any more gurus here with any ideas for me? Hate to chuck a somewhat decent little Atari just because it has no color now; especially if it is an easy fix.

 

tj

[mimo]

Is the colour dead on RF and composite outputs?

[AtariSociety]

Is the colour dead on RF and composite outputs?

no color on rf either. Tj

[+Roydea6]

Is the colour dead on RF and composite outputs?

no color on rf either. Tj

 

Run this program from basic.

 

 

POKE 623.txt

 

this will cycle Graphics Mode 0 and change character colors.

oooops ! I used a Turbo basic command in there just remove the pause 50 statement...

Edited June 11, 2010 by rdea6

[atariksi]

Is the colour dead on RF and composite outputs?

no color on rf either. Tj

 

I think you need to trace pin 21 on GTIA to its output and see what went wrong along the way. I have an Atari 800 that's B&W and it has nothing to do with the GTIA chip nor the color pot so it's some capacitor/resistor that failed.

[AtariSociety]

Is the colour dead on RF and composite outputs?

no color on rf either. Tj

 

Run this program from basic.

 

 

POKE 623.txt

 

this will cycle Graphics Mode 0 and change character colors.

oooops ! I used a Turbo basic command in there just remove the pause 50 statement...

 

This app makes the screen go completely black so NO video. hehehe

 

Had to reset to get my b&w back.

 

tj

[AtariSociety]

Is the colour dead on RF and composite outputs?

no color on rf either. Tj

 

I think you need to trace pin 21 on GTIA to its output and see what went wrong along the way. I have an Atari 800 that's B&W and it has nothing to do with the GTIA chip nor the color pot so it's some capacitor/resistor that failed.

 

as I am not a component level tech and have the know-how to trace leads and test resistors, etc... I guess that is where I end the journey. <grin> It was like 1980 when I took electronics shop at High School and learned what each ring color on a resistor was. Unless it is, replace this piece, then stick a fork in me and call me done. hehehe. I have a solder iron and could probably fudge replacing a part but finding out what part to replace and beyond my knowledge. 8-(

 

tj

[AtariSociety]

I have color again.

 

I pushed down on the adjuster pot and color popped up. I don't have the colors just right but color. The pac man ghosts in Pac Man are dark blue instead of a lighter blue. But, I have colors. I think the pit metal top was too far from the pot bottom surface. So, I pushed it downwards and colored was restored.

 

I will play again one day and see if I can get the colors just right but for now, it is decent enough.

 

tj