Quote Originally Posted by Jumper View Post
Hi,

What PIC do you use? Are you sure that pin does not have any other functions that you might have forgotten to set (comparators, AD and similar).

What if you remove the I2C device? Will the data line go low?
Many thanks for your reply. It's an 18F26J53. It's set for output so should automatically be digital. The firmware works on other board (identical). I may have to start removing components but they're all QFN types, including the PIC.