14. Head Switching Position Adjustment
Purpose: Determine the Head Switching Position during Playback. Symptom of Misadjustment: May cause Head Switching Noise or Vertical Jitter in the picture. Note: Unit reads Head Switching Position automatically and displays it on the screen (Upper Left Corner). 1. Playback test tape (VFMS0001H6). 2. Enter the Service mode in TV mode. 3. Press [5] button on the service remote control unit. 4. The Head Switching position will display on the screen; if adjustment is necessary follow step 4. 6.5H(412.7µs) is preferable. 5. Press [CH. o / p] buttons on the service remote control unit if necessary. The value will be changed in 0.5H steps up or down. Adjustable range is up to 9.5H. If the value is beyond adjustable range, the display will change as: Lower out of range: 0.0H Upper out of range: -.-H
The following 2 adjustments normally are not attempted in the field. They should be done only when replacing the CRT then adjust as a preparation.
15. Purity Adjustment
Purpose: To obtain pure color. Symptom of Misadjustment: If Color Purity Adjustment is incorrect, large areas of color may not be properly displayed. Test Point --Tape --Adj. Point Deflection Yoke Purity Magnet M. EQ. Pattern Generator Figure Mode --Input *Red Color Spec. See below
GREEN
RED
BLUE
Fig. 5 * This becomes RED COLOR if the [7] button is pressed while in service mode. 1. Set the unit facing east. 2. Operate the unit for over 30 minutes before adjusting. 3. Fully degauss the unit using an external degaussing coil. 4. Set the unit to the AUX mode which is located before CH2 then input a red raster from video in. 5. Loosen the screw on the Deflection Yoke Clamper and pull the Deflection Yoke back away from the screen. (See Fig. 6.) 6. Loosen the Ring Lock and adjust the Purity Magnets so that a red field is obtained at the center of the screen. Tighten Ring Lock. (See Fig. 5, 6.) 7. Slowly push the Deflection Yoke toward the bell of the CRT and set it where a uniform red field is obtained. 8. Tighten the clamp screw on the Deflection Yoke.
