13.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. (See page 1-7-1.) Then press the number [5] button on the remote control unit.

3.The Head Switching position will display on the

screen; if adjustment is necessary follow step 4. 6.5H(412.7s) is preferable.

4.Press [CH. o] or [CH. p] button on the 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.

14. 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

Adj. Point

Mode

Input

 

 

 

 

 

 

 

 

 

 

---

Deflection Yoke

---

*Red Color

Purity Magnet

 

 

 

 

 

 

 

 

 

Tape

M. EQ.

 

Spec.

 

 

 

 

 

 

 

 

---

Pattern Generator

See below

 

 

 

 

 

 

Figure

 

 

 

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.

1-7-6

T2202EA

Page 26
Image 26
Magnavox MWC24T5 service manual Head Switching Position Adjustment, Purity Adjustment, Green RED Blue