Don’t be mistaken that a Varistor is a Ceramic Capacitor. From the board location you would know if the particular component is a Varistor or Capacitor. Whenever there is a power surge or power problem and if the fuse blown chances is high the Varistor could be broke into half or have burnt mark. The above photo shown a burnt and splited Varistor. You can replace with a new part or you can ignore it but the power supply no longer have protection against high voltage surge and will blow all the major components if there is another surge voltage problem.