NES Blinking Gameplay

Hello
I bought a NES with the problem of red light , at the time i deactivated the lockout chip and replaces the 72 pin for a new Amazon ( lasted half a year the arrangement ) , I returned to buy another this time worked in perfection for a week. I decided to boil the original and it shows the game ( playable with the command ) but flashes

I have 20 games and all have the same problem except with the Ninja turtle which can play normalycan someone help ?
I cant find anyhere a similar problem

 

Try cleaning the games

 

thanks for replying, helped a little but still blinks any more ideas?

 

This may seem obvious but did you try it with another TV to rule out incompatible signals?

 

Not all the nes carts make use of the same pins, say tmnt doesn't use certain pins that the others do and lets say these pins that are crucial are not getting a very good connection, then it could very well be the problem. Swap out the 72 pin connector for a know good one and try again.

 

Just a thought, but do you live in an area with hard water?...

If yes, there might be a thin mineral film on the pins resulting in a bad connection.

No idea if adding a dash of vinegar would help as I don't know if or how that would affect the metal.