sanni:
You could use a Hex Editor like HxD, open both the dumped and the known good rom and compare them to see where they differ. CTRL+K and then F6 to move to the next difference.I use my TL866 to program 27C801 eproms. It's a very cheap Chinese programmer that can do a lot of stuff.
I finally got around to comparing the Hex of my Golden Nugget dump and a confirmed one. The one big difference I see is there is a large section that is all zeros in the confirmed dump. There is just no data there and in my dump there is all sorts of data. I am not sure what would cause this but it's making me question weather or not the confirmed dump CRC is correct. Without having access to another cart, I can't really say for sure but it is odd how there is a giant blank area in the file.