Added C5 (330pf) and it didn't help. Hi Erik, check if your P16PRO have 330 pf on RB7 and RB6 lines, if not add them we have schematic on our web site http://www.olimex.com/dev (PIC-PG3) you can see what and where to add Best regards Tsvetan --- PCB prototypes for $26 at http://run.to/pcb (http://www.olimex.com/pcb) Development boards for PIC, AVR and MSP430 (http://www.olimex.com/dev) -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads