At 11:32 AM 9/22/2009, Quintin Beukes wrote: >Maybe it's not connected to an LED. I'm not sure. Though I know that >it is configured as either an INPUT/OUTPUT. I've just read your most recent message, where you say that MCLR is used as a programming pin. I guess my question would be: is there a pull-up or pull-down resistor on that pin? The reason that is important is this: even if MCLR is configured as an input, it can still have an effect on the PIC, The reason is that MCLR is responsive to 3 different voltage levels: Gnd, 5V, Vpp. If MCLR is just floating, it is possible that an external static field can drive MCLR well above 5V and into the Vpp territory. The PIC will do decidedly strange things when that happens - most often, it will attempt to go into programming mode. But the effect is different with different PIC families. My suggestion, for what its worth, would be to examine the PCB and see what is connected to MCLR. If it is just floating, tie a 10K resistor between MCLR and Vdd. You may now find that your problems have vanished. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist