Quote Originally Posted by oslinux View Post
A0, A1, A2 and WP are grounded, same problem with the 2.2K resistors, only some address are writed.
Can you get rid of the 24LC512 and try a 24LC256 instead, or at least a smaller eeprom chip?

Not that it would make a difference...but it might...ya never know.
Only reason I mention it is because lots of people have used (are using) the '256, don't think I've heard of anybody using a '512 yet. They are a bit on the new-ish side (2-3 years old I'd guess, maybe...maybe not).

Also, try writing the whole eeprom, start to finish, try all $00's, try all $ff's, try a few things in between. There will probably be some sort of failure pattern in the eeprom readback itself that we might be able to see from a dump from the chip that'll narrow down the problem.