18f and 16f ics problem

hello,
is there pins problem for 16f84a and 18f452 ics because i'm using these 2 ics for my project(for different project) but after some days 1 or 2 pins of these ics get totally low and caanot be use again but programmer doesnts show the device faulty is this deu to software or what is the solution for this.
thank you

how about your schematics?
Code?

PIC's are EXTREMELY robust devices, if you've 'killed' them?, you must be doing something seriously wrong.

pic 16f and 18f problem

thanks for replay
i'm using pin no 8 of 16f84a as input i'm checking the input in software and flashing one led and buzzer.
in 18f452 i'm using pin no 3 as input which is adc channel it was working properly for onr month but now that pin is permenently low is this due to adc feature on that pin.

Mostly analogue inputs are enabled by default, so you need to specifically set them to be digital - this is a VERY common mistake!.