hi guys,
I bought some new PIC18f4685, I programmed two of them 3-4 times and now i cant program them any more. It seems they have been locked. I cant see the reason because the configuration bits are not set to code protection. If the configuration bits were wrong then i couldnt program it for a second time but i did 3-4 times and then it locked. Now, i am afraid to program the others because they may get locked.

Do you know why this happens?

 

Hello,

A couple of years ago there was this trouble with the UV erasable pics,see link, under pic erratta alert.
http://www.oricomtech.com/piclinks.htm

Greetings,
Bertus

 

Can you read them (either program memory or EEPROM)? Try erasing the entire chip first and see what happens.

 

Can you read them (either program memory or EEPROM)? Try erasing the entire chip first and see what happens.

I cant read them, it reads only FFFF. I erased all the chip from the programmers options but nothing changes. Is there any other ways to erase the chip?