How to fix power foot pedal

The tattoo foot pedal has two main problems that can occur.  One is similar to the clip cord mono plug disconnect.  To check for this, do the same thing you did with the clipcord.  Unscrew the mono plug housing, check the wires.  If they are touching, separate them, if one of them are not connected, solder or replace.  If you have one of those flat metal foot pedals, a common problem is a broken spring inside.  The foot pedal works by completing a circuit between two connectors when you press down on it.  If the spring is broken, it is either blocking the connection or causing it to short.  Some of these metal foot pedals can be unscrewed and the spring can be put back into place or replaced.  Most however are factory sealed and riveted so putting it back together is quite a challenge.  It may be more efficient to just buy a new one.