I was trying to fix my old car's key circuit. It can unlock and lock the car and is the only way to enable the alarm. This key has not worked for years.
I initially changed the batteries. The indicator led lit when the button was pushed but soon realized that the infrared led was not lighting up at all(I saw this through a camera - e.g. TV remote control infra red led is visible through a camera).
After that I examined the circuit carefully and sure enough it seems that two PCB components are missing, I found one of them in the enclosure but not the other.
Could anyone know about these circuits and guide me as to what is missing so I could replace it? Where should the 2.2KOhm resistor go? I don'h have the knowledge to figure out, please help?