4. Field scanning part: Start the sawtooth signal formed in TDA8844 to output from pin 46 and 47, and directly input it to 1 pin of field ICMTV 137B; The other path is shaped and amplified by ICM33 and CA0007AD, and then input to pin 7 of domain ICMTV 137B. After being stimulated and amplified by IC(MTV 137B), the other path is output from five pins, which provides linearly varying currents for the deflection coils of R, G and B fields respectively, forming a deflection magnetic field, which deflects the electron beam from top to bottom, completing the field scanning work, and thus improving the stability of the whole machine.