Amiga 2000 green screen

[Oldsmobile_Mike]

Google will give you links to a hundred different pages that tell you a green screen is indicative of a chip memory problem:

http://wiki.classicamiga.com/Amiga_boot_error_code_colours

https://en.wikipedia.org/wiki/Power-on_self-test#POST_sequence_of_Amiga

http://www.amiga.org/forums/archive/index.php/t-4216.html

Etc.

Now if you want to really solve this problem you're going to need to post more information.  Have you tried removing all cards?  Reseating all socketed chips?  Has the battery leaked, or has it been removed?  (leaking batteries can cause all manner of havoc to an Amiga motherboard)  Etc., etc.

[Oldsmobile_Mike]

no i dont try , if it is chip is it possible to fix , is that chip expensive?

Doing things like reseating all of the custom chips and cleaning sockets won't cost you anything but time, same as researching and learning about the potential causes of this problem.  Unless your battery has leaked all over the board there's very few things an A2000 can't be recovered from.