brakes are locked up

More likely the abs system. Is the abs light on?

Same thing happened to mine, would like to know what to do after changing pads, one caliper, and turning rotor. Still doing it.

If you have abs and traction control it very well could be the electric control valve for those systems. There are solenoids inside that stick, it wont show a code unless the electric side dies. If the valve sticks it just wont let fluid go to the brake or possibly return from the brake depending on which one sticks.