Finishing up owner-assisted annual which was going well until today.  Airplane is on jacks, did a couple of gear swings, all good.  But after playing with the manual extension when I try to retract the gear the Gear Actuator circuit pops.  This is what the service manual says:   TROUBLE: Gear will not retract & Landing Gear Actuator C/B trips. PROBABLY CAUSE: Manual engage handle in engaged position REMEDY: Disengage Manual System   The manual extension lever is