I changed power cord to 3 prong, now i see PF code Does this machine take 3 prong?

All electric dryers are compatible with the 3 prong cords, if you have a 3 prong outlet to plug it in at. You must have a loose wire on the power cord or a wire fell of the dryer terminal. PF means power failure so the control is not getting the proper voltage or the voltage is dropping when the dryer is running. Check the cord connection at the dryer terminal. Make sure the middle wire on the dryer cord is connected to the middle terminal on the dryer the other two don't really matter as long as there is one on each side. Make sure the connections are tight and that the screws are all the way down and pressing the connector on the cord firmly against the terminal block contact. Then check and make sure the the wires on the dryer that connect to the dryer terminal block did not fall off in the process. If the wiring checks out ok then you may want to change out the breaker for the dryer and if that does not help the main control board on the dryer may be failing.