Not sure if "corrupting" is the right word, but let me give the whole story here.
I was playing on my Atari 2600 4-switch model for a while and everything was working fine. Played about 10 games. All the games worked on first insert, even though some haven't been cleaned.
Then I put in the Asteroids cartridge and turned it on. I hit Reset to start, but the spaceship is invisible. I take out the cartridge, blow into it (exposing the contacts first of course) and blow into the 2600 cartridge slot. Put it back in, turned it on, hit Reset, and this time the spaceship is visible but the enemy sprites (asteroids) aren't.
So I tried Defender. Put the cartridge in and hit Reset. Again, the spaceship is invisible as well as certain enemies. Tried Joust, same thing. Tried Yar's Revenge, either the brown blocks or the rainbow strip is invisible. Obviously none of these games are playable because of this.
Then I put these games in my Atari 2600 Jr. to see if they would work in a different unit. But no, same problem. Tried the games in a ColecoVision with Expansion Module #1 (plays Atari 2600 games) and same problem there too, even on different hardware. But the real kicker here is that all the games I didn't play on the original Atari 2600 4-switch model after this epidemic started happening worked fine on the other two consoles.
I tried unplugging and replugging the A/C, cleaning the cartridges with rubbing alcohol, trying different game modes, etc, but nothing has brought back those 4 cartridges to proper working order. The 4-switch console seemingly has corrupted those 4 cartridges. Thankfully they aren't expensive games.
So question is, what do you think could have happened in the 4-switch console within about 60 seconds (between cartridge swap) that could have ruined all subsequent games inserted? I even took it apart and nothing seems physically wrong. Could it be fixable or would I be better off with a new one? I don't mind getting a new one; I prefer the 6-switch model anyway.
This is SMWC of course, so you guys probably have more experience with the SNES, but figured I'd try asking anyway. I looked online and can't find a trace of information about this or anyone else with any kind of similar problem.