ok.. updated it a lil bit now i have blue ones for activity and green for idle.. everything is in place.. and the green lights up when its idle.. but when i connect the HDD wires to a power source... ie 3 V battery or 5 V from the psu on different polarities... nothing happens however... i notice that when i touch (ground) the 6th pin of the 4n26/25, the blue ones get brighter and greens one go dimmer.... maybe there might be some differences between uk chips and malaysian chips... mines a liteon 4n26 i also have a 4n25 if the 26 is not suitable... if this happens.. what can i do to correct it?
Pin 6 is connected to the base of the transistor so it will affect the output if you touch it due to pickup. If you have connected 3V or 5V directly to the input of the isolator and not used a resistor in series you have almost certainly destroyed the isolators internal LED. Try a new opto isolator and this time put a resistor in line with the 5V when testing it. A value between 330 - 470 ohms will do. When the circuit is connected to the mobo the resistor is not needed because the mobo limits the led current itself.
