The load does not turn ON when the Switch is pressed. Why is this?

1. There may be a contact failure.

Causes:

The switch is not pressed sufficiently. 

A general-purpose switch (with silver contacts) is being used for a microload (electronic circuit).

2. The contacts may be welded. 

3. The internal spring may be broken. 

4. The operating speed may not match. 

5. The operating frequency may not match.