Sounds a lot like floating pins to me. Check the reset and interrupt
pins for starters. You may get lucky.

-- Rich



WF wrote:
>
>     Hi again
>
>   We did a project where our PIC uses a 4011 and 4017 for display
> informations in 10 seven segment display...We use the TIMER 0 interrupt for
> control the time between writes on each DISPLAY...all works very well!
>     But, when i touch on the top of PIC16C873, it resets...and sometimes
> locks...and the WATCH-DOG doesn't work more and the EXTERNAL RESET doens't
> have more effect....for reinitialize the execution, we have to take off the
> power suppy and reestart it...
>
>      How should we proceed to solve this problem?
>
>     Thanks for all!
>
>     Miguel Wisintainer
>     Marcos Feller
>     Josi Fausto Gil Zift