Atari 2600 problem, wavy picture

[Dennis90]

I have AV modded an Atari 2600 with the mod with 2 resistors and a capacitor, i have done it all correctly and i had tested it before, but now it does not seem to work, the picture is like really wavy and bad and so, so you cant see whats going on the screen, the game plays tho and i hear sounds. so any ideas what can be wrong? hope someoen can help! and i took out the 3 big ICs in the atari and tried with 3 other ones from another system, but its the same problem so those seem to work at least.

[Thibr]

Any pictures showing us your display issues ?

[freewheel]

You said it worked before - are you using it now on the same TV as before? A lot of the simpler AV mods give video signals that are, shall we say, not very strong. I've done some mods that work perfectly on one TV but are almost unviewable on others. I don't sell AV mods to unsuspecting buyers for this very reason - you never know what they're hooking up to. If you have an old VCR around, run the AV inputs through that and then into your TV. That'll usually rule out a weak video signal.

 

You said 2 resistors and a cap, I'm not familiar with that mod as I usually put pots everywhere - I find it helps to troubleshoot/fix issues similar to what you're seeing. You could always try a re-mod with pots, but I know how little fun that is.

 

Failing that, it could simply be that one of your solder joints has come loose (or was never very good in the first place - I'm a terrible solderer, I know about this first hand). Again involves basically re-doing things, not fun.

 

Did you completely remove the RF output? If it's still intact, try checking the RF output as a comparison. It's highly unlikely it's the 2600 itself (in the sense of the chips) as only one is involved in video anyway. If the game's playing and sounds OK, then it's likely your output circuit - the question is where and why.

 

Wish I could be more helpful. Hard to diagnose further without seeing pics of the screen, and your mod.

[Dennis90]

i have a pic of it now so you see how it looks like, and yes i use it on same TV as before, and other consoles work fine on it and so also.

 

Aha but yeah, i dont have any pots and so, but understand how you mean, it wil be easy to adjust and so then, but i heard that mod is very reliable tho! o.o

 

This is kinda like the mod i made also: http://www.coolretroprojects.com/Atari_2600_AV_Mod_Installation_Guide.pdf

 

and the mod has these 3 components: https://dl.dropboxusercontent.com/u/9400754/MMGN/Atari%20AV%20Mod/Transistor%20Mod/Transitor%20mod-watermark.jpg

 

and sorry btw i meant transistor before, not capacitor!

 

The Atari i use btw is a PAL 6 switcher.

 

And yes the RF is taken out now, so cant try that

Edited June 22, 2014 by Dennis90