Magnavox MWC24T5 service manual White Balance Adjustment, Sub-Brightness Adjustment, Smpte

7. White Balance Adjustment

Purpose: To mix red, green and blue beams correctly for pure white.

Symptom of Misadjustment: White becomes bluish or reddish.

	Test Point	Adj. Point	Mode	Input
	Screen	[CH. o / p]	RF	White Raster
		buttons		(APL 100%)
	Tape	M. EQ.		Spec.
		Pattern
---		Generator,	See below
		Color analyzer
		Figure

Color Analyzer

Fig. 3

Note: Use service remote control unit

1.Operate the unit more than 20 minutes.

2.Face the unit to the east. Degauss the CRT using a degaussing coil.

3.Input the White Raster (APL 100%).

4.Set the color analyzer to the CHROMA mode and after zero point calibration, bring the optical receptor to the center on the tube surface (CRT).

5.Enter the Service mode. Press [VOL p] button on the service remote control unit and select “C/D” mode. (Display changes “C/D”, “7F” and Initial Setting cyclically when [VOL p] button is pressed.)

6.Press [4] button on the service remote control unit for Red adjustment. Press [5] button on the service remote control unit for Blue adjustment.

7.In each color mode, press [CH. o / p] buttons to adjust the values of color.

8.Adjust Red and Blue color so that the temperature becomes 9200K (x: 286 / y: 294) ±3%.

9.At this time, re-check that horizontal line is white. If not, re-adjust Cut-off Adjustment until the horizontal line becomes pure white.

10.Turn off and on again to return to normal mode. Receive APL 100% white signal and confirm that Chroma temperatures become 9200K (x: 286 / y: 294) ±3%.

Note: Confirm that Cut Off Adj. is correct after this adjustment, and attempt Cut Off Adj. if needed.

8. Sub-Brightness Adjustment

Purpose: To get proper brightness.

Symptom of Misadjustment: If Sub-Brightness is incorrect, proper brightness cannot be obtained by adjusting the Brightness Control.

Test Point	Adj. Point	Mode	Input
---	[CH. o / p]	---	SMPTE
	buttons		7.5IRE
Tape	M. EQ.		Spec.
---	Pattern	See below
	Generator
	Figure

White	Black
	This bar
	just
	visible
	Fig. 4

Note: SMPTE Setup level --- 7.5 IRE

1.Enter the Service mode. (See page 1-7-1.) Then input SMPTE signal from RF input.

2.Press [PICTURE] button. (Press [PICTURE] button then display will change BRT, CNT, COL, TNT, V-T, and SHP). Select BRT and press [CH. o / p] buttons so that the bar is just visible (See above figure).

1-7-4 T2202EA