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Baird M676: Frame Cramp
Very poor field linearity, lack of height, field locked up at one end of the control with bounce.
Tried fitting a new PCL805, replaced C163, C168, C172,C176, C169, C164 and C175. Checked R131, R132, R155, R144 and replaced interlace diode x11. Height linearity and form control all operate but cannot correct the scan fault.
Checked and found the thermistor in the field scan coils to be open circuit, all the scan current going though the 15 ohm resistor. Shorting out the thermistor resulted in full restoration of field scan. The thermistor does need replacing, if left out of circuit the field scan may be reduced in height by about ½” when the scan coils are fully warmed up.