Adjustment Instructions; Convergence Adjustment; Screen Voltage Adjustment; White Balance Adjustment - LG RT-21FD90VQ Service Manual

1. Application Object
These instructions are applied to all of the color TV, MC-049B.
2. Notes
(1) Because this is cold chassis, it is not necessary to use an
isolation transformer. However, the use of isolation
transformer will help protect test instrument.
(2) But, operate it using a transformer between the power
supply line and chassis input to prevent electric shock and
to protect the test instrument.
(3) All adjustments must be done in correct sequence.
(4) However, for the better productivity, it can be changed in
pre-permitted range.
(5) Environment conditions : If not specified, it must be done in
following conditions.
1) Temperature : 25±5°C
2) Humidity : 65±10%
(6) Power supply of a SET which is adjusted is (100-240V~)
±10%, 50~60 Hz
(7) If not specified, the receiver must be operated for more
than 20 minutes period to the adjustment.
(8) Signal : Receive the standard color signal (65dB±1dB uV)
LG standard signal means the digital pattern,EU
05 CH(PAL)
3. Focus voltage adjustment
(1) Receive the LG standard pattern
(digital pattern, PAL : Fig 1 & NTSC : Fig2)
(2) Set the picture condition on 'STANDARD' mode.
(3) Adjust the Focus volume of FBT for the best focus of
horizontal line A, vertical line B.
<Fig 1>
4. Purity & Convergence adjustment

4-1. Purity adjustment

(1) Preparation
1) Receive the RED Raster Pattern for purity adjustment.
(11CH)
2) Demagnetize the CPT and cabinet with a degaussing coil.
(2) Adjustment
1) Pre-adjust the static convergence(STC) with 4 and 6-
pole magnet.
2) Push the DY all way to the CPT panel.

ADJUSTMENT INSTRUCTIONS

<Fig 2>
3) Turn the purity magnet (2-pole magnet) so that the green
portion of left side and the blue portion of right side have
same portion.
4) Pull the DY slowly and fix it when the whole screen
become red.

4-2. Convergence adjustment

(1) Preparation
1) Receive the Cross Hatch pattern for convergence
adjustment. (09CH)
2) Let the contrast at the adequate luminance level.
(2) Adjustment
1) Converge the RED vertical line and BLUE vertical line in
the same line by changing the angle between the 2 tabs
of the 4 pole magnet.
2) Converge the RED horizontal line and BLUE horizontal
line in the same line by turning the 2 tabs of the 4pole
magnet. This time, do not changing the angle between
the 2 tabs.
3) Converge the R,G,B vertical line in the same line by
changing the angle between the 2 tabs of the 6pole
magnet.
4) Converge the R,G,B horizontal line in the same line by
turning the 2 tabs of the 6pole magnet. This time, do not
change the angle between the 2 tabs.
5. Screen voltage & White balance
adjustment
Screen adjustment mode:INSTART for line SVC MODE then
ADJ.
Vary screen volume of the FBT till horizontal line appear and
stop to the point that it starts to disappear.

5-1. Screen voltage adjustment

(1) Receive the PAL or SECAM(NTSC) signal into RF mode
regardless of channel.
(2) If you press the "ADJ"button in LINE SVC mode(IN-START
button),the LINE SVC mode changes to screen adjustment
mode.
(3) Adjust the screen volume of FBT jack,When width line is
seen turn the FBT screen volume at the position of
disappearance it.
(4) Press the TV/AV button to exit SVC mode.

5-2. White balance adjustment

- Prior to this adjustment, the Screen Voltage adjustment must
be finished.
(1) Necessary Instrument
1) Auto White Balance Meter
2) Color Analyzer (CA-100)
3) Factory SVC Remote control
(2) Adjustment
1) Make the picture luminance 35±10 Ft-L by changing the
"CONTRAST" and "BRIGHTNESS".
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