Shrinkage distortion is a problem of pincushion correction circuit or S correction circuit. In addition to triode, there are diodes and resistors in the pillow calibration circuit. Also check the power circuit of the triode and the sawtooth signal of the shaping field. The upper part is stretched and the lower part is curled, so there is something wrong with the field linearity. Check the capacitance and deflection coil of AC negative feedback circuit and sawtooth wave forming circuit.