Here is my experience trying to fix my Atari 2600A:
I wanted to play some games on my Atari, initially everything was fine but there was a very slowly vertical rolling on my LCD TV, that's when all started ....
I opened the case, cleaned the inside with contact cleaner, adjusted the video/sound synthesizer, removed and reinserted the 3 chips (by mistake, I placed TIA backwards and I didn't turn on, I placed it back correctly and turn it on, it partially work again)
I did the mod on the Atari following these 2 articles: http://www.coolretroprojects.com/Atari_2600_AV_Mod_Installation_Guide.pdf and https://www.instructables.com/id/ATARI-2600-Video-Composite-mod/#CSJUVVMJQ0SNBGI
- Vertical screen rolling (up to down, medium speed).
- No color at all, just black and white.
- Some sounds are missing.
- Controllers directions work fine (up/down/left/right) but fire button doesn't work ...
- There is a rapid-fire sound even when both controllers are unplugged (it seems there is only a sound because I do not see the bullets coming out on combat game for example)
- Some Game logic is incorrect, for example, while playing combat, while going forward the tank start jumping around instead
I suspect the TIA got damaged, so I am contacting Best Electronics - Bradley Koda to see if he has one for sale ...
I have another Atari Jr and I tested controllers, power adapter and cables and they are fine.
If a chip is placed backwards it will get damaged?
Do you think those issues are because damaged TIA?
Probably by touching the chips any got damaged?
Why vertical rolling screen happen?