PURITY & CONVERGENCE ADJUSTMENT

Caution:

Convergence and Purity have been factory aligned. Do not attempt to tamper with these alignments.

However, the effects of adjacent receiver components, or replacement of picture tube or deflection yoke may require the readjustment of purity and convergence.

5.Reconnect the internal degaussing coil.

6.Position the beam bender locking rings at the 9 o'clock position and the other three pairs of tabs (2,4 and 6 pole magnets) at the 12 o'clock position.

 

DEFLECTION YOKE

6-POLE

 

PURITY &CONVERGENCE

MAGNETS

 

MAGNET ASSEMBLY

PURITY MAGNET(2-POLE)

 

6-POLE

 

 

 

4-POLE

 

X-AXIS YOKE

MAGNET

 

POSITIONING

 

RUBBER

(L/R PURITY)

 

 

 

WEDGES

PURITY MAGNET

 

 

 

 

4-POLE

 

 

GLASS CLOTH TAPE

CONVERGENCE MAGNET ASSEMBLY

¯Purity Adjustment

This procedure DOES NOT apply to bonded yoke and picture tube assemblies.

The instrument should be at room temperature (60 degrees F or above) for six (6) hours and be operating at low beam current (dark background) for approximately 20 to 30 minutes before performing purity adjustments.

CAUTION: Do not remove any trim magnets that may be attached to the bell of the picture tube.

1.Remove the AC power and disconnect the internal degaussing coil.

2.Remove the yoke from the neck of the picture tube.

3.If the yoke has the tape version beam bender, remove it and replace it with an adjustable type beam bender (follow the instructions provided with the new beam bender)

4.Replace the yoke on the picture tube neck, temporarily remove the three (3) rubber wedges from the bell of the picture tube and then slide the yoke completely forward.

7.Perform the following steps, in the order given, to prepare the receiver for the purity adjustment procedure.

a.Face the receiver in the "magnetic north" direction.

b.Externally degauss the receiver screen with the television power turned off.

c.Turn the television on for approximately 10 seconds to perform internal degaussing and then turn the TV off.

d.Unplug the internal degaussing coil. This allows the thermistor to cool down while you are performing the purity adjustment. DO NOT MOVE THE RECEIVER FROM ITS "MAGNETIC NORTH" POSITION.

e.Turn the receiver on and obtain a red raster by increasing the red bias control (CW) and decreasing the bias controls for the remaining two colors (CCW).

f.Attach two round magnets on the picture tube screen at 3 o'clock and 9 o'clock positions, approximately one (1) inch from the edge of the mask (use double-sided tape).

- 13 -

Page 13
Image 13
LG Electronics 32FZ4D-UA, 30FZ4D service manual Purity & Convergence Adjustment, Axis Yoke, Positioning