Pull down resistors
The pull down resistors R2, R3, R4, R5 and R13 have inappropriate value of 100 ohms. Because of this is impossible to drive 74HC04D ports to high logic value.
I changed the resistor from 100 ohms to 100k ohms and works fine.
The pull down resistors R2, R3, R4, R5 and R13 have inappropriate value of 100 ohms. Because of this is impossible to drive 74HC04D ports to high logic value.
I changed the resistor from 100 ohms to 100k ohms and works fine.