Hi, Background: I have done a programe that includes an IR input from a remote control, output to ports for relays and IIC to Serial Memory 24C08 interface. I am using 2 new 16F876 for development since last 2 days. Observation: One of the PIC(no1) functions 100% perfectly. The otherPIC (No2) also is getting programmed correctly by the same WARP 13 A programmer, the IR, and ports work well but the IIC serial communication to the memory does not work!!! Thus there is a partial response. I loaded a 16C72 with the same software,( that was the chip I had and the code was designed to eventually use a 16C72 with 24C08 instead of a 16F876), and it also worked well (100% including IIC). Questions: 1. Have U also observed such a behaviour of a PIC giving partial response despite the programming being reported OK. 2. Any reasons that could explain the above (The PIC is new and 2 days old) 3. If the Chip is partially defective, what is the most reliable method of knowing it apart from trial and error and benchmarking with 1 or 2 more chips. Thanks, Rajiv Thakur -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads