Light bulbs only require a simple switch to operate - a PCB control would make the fire overly complex and overly costly.
If your bulbs are of the screw-in type [ES] then consider that the central contact of the bulb may not be making contact with the central contact of the lamp holder.
If you slightly bend a holder's spring contact it may be a solution - be sure to have it unplugged - make yourself a small hook - use a mirror to look down the hole if necessary.
I offer this suggestion because it's happened to me - not all bulbs have the same dimension and the central contact can become bent and no longer touch a shorter replacement bulb.
But I only guess...
Good Luck...
November 2016