Convergence Adjustment; Purity Adjustment - Emerson SC319C Service Manual

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.

13.Purity Adjustment

Purpose: To obtain pure color.
Symptom of Misadjustment: If Color Purity Adjust-
ment is incorrect, large areas of color may not be
properly displayed.
Test point Adj. Point
Deflection Yoke
---
Purity Magnet
Tape M. EQ.
--- Pattern Generator
Figure
GREEN
* This becomes RED COLOR if push 7KEY with a
service mode.
1. Set the unit facing east.
2. Operate the unit for over 30 minutes before adjust-
ing.
3. Fully degauss the unit using an external degauss-
ing 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 Mag-
nets 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.
Mode Input
--- *Red Color
Spec.
See below.
RED
BLUE
Fig. 5

14. Convergence Adjustment

Purpose: To obtain proper convergence of red, green
and blue beams.
Symptom of Misadjustment: If Convergence Adjust-
ment is incorrect, the edge of white letters may have
color edges.
Test point Adj. Point
C.P. Magnet (RB),
--- C.P. Magnet (RB-G),
Deflection Yoke
Tape M. EQ.
--- Pattern Generator
CRT
DY WEDGE
DEFLECTION YOKE
C.P. MAGNET (RB)
C.P. MAGNET (RB-G)
RB
G
1-7-6
Mode
Dot Pattern
---
Crosshatch
Spec.
See below.
Figure
RB RB-G
COIL PURITY
SCREW
RING LOCK
SCREW
C.P. MAGNET CLAMPER
C.P. MAGNET
COIL CLAMPER
Fig. 6
R
R
G
G
B
B
Fig. 7
RB
Fig. 8
T7300EA
Input
or
G