It is my first project with a PIC microcontroller, so I am sorry if my question seems too basic.
I have programmed the PIC as a frequency counter with two inputs: one input for a PLL, and another input for a clock (I am not using an external oscillator... This clock is used as a windows of 1 second so that the PIC can count on that 1 second how much pulses does the PLL make). However, the big problem is the following: Each part works well alone with 5 volts of output, but when I connect the clock to the microcontroller's input, the output voltage of the clock drops from 5 volts to less than 1 volt. With less than 1 volt, the PIC is not able to recognize my 1 second windows. Why does this happend? How can I avoid or correct this problem?
Schematics of clock: The output is Q1 of 4018. That output goes directly to the input of the PIC (the input of the pic is where that square signal of the first image goes) Evcerything is fed with 5 volts