General Adjustment; White Balance Adjustment - Daewoo TVZ 1321 Service Manual

GENERAL ADJUSTMENT

1. GENERAL
In the majority of cases, color television will need only slight
touch-up adjustment upon installation. Check the basic
characteristics such as height, focus and sub-bright.
Observe the picture for good black and white details without
objectionable color shading. If color shading is evident,
demagnetize the receiver. If color shading still persists, per-
form purity and convergence adjustments. this should be all
that is necessary to achieve optimum receiver performance.
2. VERTICAL HEIGHT ADJUSTMENT
1) Tune in an active channel.
2) Adjust brightness and contrast control for a good picture.
3) Adjust vertical height control (R304) for approximately
one half inch over scan at top and bottom of picture
screen.
3. FOCUS ADJUSTMENT
1) Tune in an active channel.
2) Adjust brightness, sharpness and contrast controls for a
good picture, sharp scanning lines and/or sharp picture.
4. RF AGC ADJUSTMENT
1) Tune in an active channel.
2) Using the attenuator, apply the signal of 60dBµV to the
Antenna input terminal
3) Turn RF AGC control (R106) so that it is 1.0V±0.3V
lower than maximum voltage.
5. HIGH VOLTAGE CHECK
High voltage is not adjustable but must be checked verify
that the receiver is operating within safe and efficient design
limitations as specified :
1) Operate receiver for at least 15 minutes at 100-140V AC
line.
2) Set brightness, sharpness, contrast and color controls to
minimum position (Zero beam).
3) Connect an accurate high voltage meter to CRT anode.
The reading should be as follows.
13"
20"
If a correct reading cannot be obtained, check circuitry for
malfunctioning components.
6. X-RADIATION PROTECTION CIRCUIT TEST
When service has been performed on the horizontal deflec-
tion system, high voltage system or B+ system, the X-RADI-
ATION PROTECTION circuit must be tested for proper
operation as follows:
1) Operate the receiver for at least 15 minutes at 120V AC
line.
2) Confirm high voltage protector when R409 of power
PCB is connected to 30kΩ(1/4w) in parallel.
3) If high voltage protector is operated, remove 30kΩ(1/4w)
and confirm whether high voltage protector is still on.
4) Confirm normal operation on sound and video when
24KV~26KV
26KV~28KV
4
R410 is shorted.

7.WHITE BALANCE ADJUSTMENT

1) Receive MONOSCOPE PATTERN signal.
2) Set the each BIAS VR (VR903, VR904, VR905) and
DRIVE VR(VR901, VR902) to center position and Mini-
mize SCREEN using SCREEN VR on the side of FBT.
3) Open LEVER SW(S901) of CRT PCB.
4) Make straight and horizontal line by pushing service
key(V/H) on the SERVICE remocon.
5) Turn the SCREEN VR slowly until first color is bright-
ened and turn the appropriate BIAS VR to the counter-
clockwise until that line's color disappears.
6) Turn the SCREEN VR slowly again until another color is
brightened and turn the appropriate BIAS VR to the
counter-clockwise until that line's color disappears.
7) Turn the SCREEN VR slowly again until third color is
brightened and turn the appropriate BIAS VR to the
counterclockwise until that line's color disappears.
8) Adjust the BIAS VR to become white appropriate line by
turning the BIAS VR in concerned with step 4-6, and 4-7
to clock direction (to be brightened).
9) Although you did step 4-5, 4-6, 4-7,
If it is not bright each step's color but bright first color,
stop turn the SCREEN VR at the position which color is
hardly to be seen, and concerned BIAS VR to clock
direction (to be brightened).
10) Turn LEVER SW(S901) of CRT PCB on.
11) Let the straight and horizontal line disappear by pushing
service key(V/H) on the SERVICE remocon.
12) Set CONTRAST to maximum and set brightness to
center, and adjust WHITE BALANCE using R's and B's
DRIVE VR.
13) Inspect TRACKING for WHITE BALANCE by varying
CONTRAST and brightness.
If tracking not correct, Repeat step 4-5 to 4-9.
NOTE :
1. When performing any adjustments to resistor controls
and transformers use non-metallic screw driver or TV
alignment tools.
2. Before performing adjustments TV set must be on at
least 15 minutes.