Hitachi model 43fwx20b question?

I have an Overflow error message come up upon completion of my magic focus operations. Overflow.(4)
Says to check the convergence yoke return resistor values. Any clue as to how I do this? Do I have to have the resistor replaced? If so, Can I do this myself or call in a technician? If I can do this myself, How do I get a replacement part and proceed?
Chasis Model: DP24
Remote: CLU-4321UG