Fix for gray screen on NES?

[Ol Nes]

In a minute or two my NES stopped working and I've never encountered this before.  It's a gray screen with a game in and a blinking gray screen with no cart.  It's not a problem with the 72 pin connector or games.  Is this a specific problem or could it be caused by a number of things?  All info welcome...Thanks!

[Frank_fjs]

How do you know it's not the cartridge slot?

99% of the time this is the cause of a grey screen, and the slot either needs a good clean and pins bent back or replaced with a new one.

[Ol Nes]

I have replaced many 72 pin connectors - I have a new one in the system which works perfectly with another working system, so thats not it.  Thanks for the reply.

[MarioMania]

Clean the game

[Pemdawg]

Agreed. Every Greg screen I have had was from bad contact. Clean your games well, and say goodbye to Greg screens :-)