In-circuit PIC Problem

Haha!! VICTORY! I finally managed to find the problem. You were right, mr. Ian and Alec_t. The OSCCAL value has been erased during reprogramming and this was the cause of the PIC operation problem. What I have done to solve the problem was changing the internal oscillator with an external RC oscillator. I have seen on the google that there are solutions to restore the factory calibration value of the oscillator. However, now I managed to solve a BIG problem that stopped me from experimenting.

Thank you everyone for the tips you told me!!!!

And there you have it!! Glad its solved