Nonetheless, many low-end power supplies often cut off important MOV components to save cost. For power supplies equipped with MOV components, the presence or absence of a surge suppressor is no longer important, because the power supply already has the function of suppressing surges.
Disc capacitors, usually blue, these capacitors are usually also called “Y” capacitors; C3 is a metallized polyester capacitor, usually 100nF, 470nF or 680nF, also called “X” capacitors; some power supplies are equipped with two X capacitor, connected in parallel with the mains