hi. i recently bought like 4 SNES a SEGA CD and an Intellivision (all broken)
and im trying to fix the stuff..

after some examination ive noticed that the SNES had the following symptomes.

Test cart Super Mario World.
AV RCA cable.

1. Powers up, shows Nintendo Logo, starts playing sound but black screen.
2. Powers up, used to display picture and work but now its black but plays sound.(had a water damage but have been cleaned using electronic cleaning alcohol)
3. Powers up, shows picture but the background is red and sprites do look broken.. (some dont display correctly).
4. Had a cracking sound issue but is now fixed.

any kind of help would be useful.