* Safety precautions
1. It is safe to adjust after using insulating transformer
between the power supply line and chassis input to
prevent the risk of electric shock and protect the
instrument.
2. Never disconnect leads while the TV receiver is on.
3. Don't short any portion of circuits while power is on.
4. The adjustment must be done by the correct appliances.
But this is changeable in view of productivity.
5. Unless otherwise noted, set the line voltage to 220Vac+_
20%, 50/60Hz.
* Test Equipment required
1. Swee p Generator
2. Marker Generator(38.0MHz: Picture/32.5MHz: Sound)
3. Alignmen t Scope(5121A)
4. Patter n Generator(PAL/SECAM)
5. DC Power Supply
6. Color analyzer
7. Multimeter(Volt meter)
* VCO (Voltage Controlled Oscillator)
Adjustment
1) Turn on DC power supplies.
2) Adjust VCO ADJ. coil(L501) so that the level of Picture
Carrier (PC) may be at the lowest position as shown Fig.
2.
NOTE:
When performing this adjustment, if there are 2
adjusted point in VL501, select the lower core
position.
* RF AGC (Auto Gain Control)
Adjustment
The RF AGC control VR501 was aligned at the time of
manufacture for optimum performance over a wide range
conditions. Readjust VR501 should not be necessary
unless unusual local conditions exist, such as;
1)
Channel interference in a CATV system
2) Picture bending and/or color beats, which are unusually
due to excessive RF signal input when the reciever is
too close to a transmitting tower or when the receiver
is connected to an antenna distribution system where
the RF signal has been amplified.
In this case, the input signal should be attenuated(with
pad or filter) to a satisfactory level.
3) Picture noise caused by "broadcast noise" or weak
signal.
If the broadcast is "clean" and the RF signal is at least
1mV (60dBu), the picture will be noise free in any area.
- 1 -
ADJUSTMENT INSTRUCTIONS
Preparation for VCO Adjustment
1. Connect the measuring equipment to the TV as shown in
Fig. 1
2. Set RF output level of Sweep Generator to 90dBuV.
MAIN BOARD
5
1
7
48
3.3K
IC401
(JP 6)
VL501
VCO ADJ.
CK
0.01uF
Z101
(JP 1)
C533
(JP 3)
L504
(JP 4)
TUNER
Hor
Ver
Alignment
Scope
SWEEP S.G
with Marker
DC POWER
SUPPLY
5.0 + 0.1V
DC POWER
SUPPLY
16 + 0.5V
IC501
RF
out
J9
AGC
ADJ.
Fig. 1: Connection Diagram of Equipment for VCO Adjustment
SC (Sound Carrier)
: 32.5 MHz
PC (Picture Carrier)
: 38.0 MHz
Fig. 2: Output waveform on Alignment Scope
Test Point
: J9(AGC ADJ.) or Observing Display
Adjust
: VR501
Test Point
: JP4(L504)
Adjust
: VL501
Adjusting the VR501(RF AGC) control to one end of
rotation will usually cause a relatively poor signal to noise
ratio;
Adjusting to the other end of rotation will usually cause a
degradation of over load capabilities resulting on color
beats or adjacent channel interference.
For the best results, adjust VR501 contol while
performing on all other local channels, or Refer to the
following Table 1.
* Vertical Height, Center Adjustment
1) Tune the TV set to receive a digital test pattern.
2) Set standard picture mode(contrast: 80, bright :60,
color: 50).
3) Adjust the Vertical height control (VR301) so that the
circle of a digital test pattern may be located within
the effective screen of the CPT.
4) Adjust the Vertical center control (VR302) for
obtaining geometric center of valuable display
vertically.
* Focus A djustment
NOTE: This adjustment should be performed after
warming up for 10 minutes.
1) Tune the TV set to receive a digital test pattern.
2) Adjust the Focus control for the best overall focus.
* Horizontal Center Adjustment
1) Tune the TV set to receive a PAL digital pattern.
2) Adjust the Horizontal center control(VR502) for
obtaining geometric center of valubale display
horizontally.
* Scr een & White Balance
(color temperatur
e) Adjustment
NOTE:
1) Set all the controls (VR901-VR905) on CPT Board to
geometric center position.
2) Set the standard mode (contrast : 80, bright : 60, color : 50).
3) Set the AV mode, adjust and set the screen volume of
FBT at just cut-off position(No AV input signal).
4) Set the TV mode, tune the TV set to receive white
pattern.
5) By using color analyzer (white balance checker), adjust
X position equals to 281+_8 and Y position equals to 288
+_8, it means that color temperature is 10,000+_800 at
low light (4.5ftL) and high light (over 45ftL).
- 2 -
Tuner P/N
113-118C/D/F
113-238H
6700VMV001A
Maker
LG-ALPS
LG-ALPS
SANYO
REMARK
RF 60+_1dBuV
RF 60+_1dBuV
RF 60+_1dBuV
Adjustment Voltage
5.7+_0.1Vdc
6.0+_0.1Vdc
4.9+_0.1Vdc
Test Poin t
: Observing display
Adjust
: VR301 (Vertical Height)
VR302 (Vertical Center)
Test Poin t
: Observing display
Adjust
: Focus control of FBT
Test Poin t
: Observing display
Adjust
: VR502
1. This adjustment should be performed after
warming up for 20 minutes.
2. The color bias controls (VR901, VR902, VR903)
affect the low light (dark) area of the picture
while the color drive controls (VR904, VR905)
affect the high light (white) areas.
3-2
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
need to readjust purity any convergence.
* 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 a 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.
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.
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).
DEFLECTION YOKE
PURITY &CONVERGENCE
MAGNET ASSEMBLY
RUBBER
WEDGES
GLASS CLOTH TAPE
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PURITY MAGNET
6-POLE
4-POLE
4-POLE
MAGNET
CONVERGENCE MAGNET ASSEMBLY
6-POLE
MAGNES
PURITY MAGNET(2-POLE)
X-AXIS YOKE
POSITIONING
(L/R PURITY)
6-POLE
MAGNETS
CONVERGENCE MAGNET ASSEMBLY
3-3
8. Referring to above, perform the following two steps:
a. Adjust the yoke Z-axis to obtain equal blue circles.
b. Adjust the appropriate beam bender tabs to obtain correct
purity (four equal circles).
9. After correct purity is set, tighten the yoke clamp screw and
remove the two screen magnets.
10. Remove the AC power and rotate the receiver 180 degrees
(facing "magnetic south").
11. Reconnect the internal degaussing coil.
12. Turn the receiver on for 10 seconds (make sure the receiver
came on) to perform internal degaussing, and then turn the
receiver off.
13. Unplug the internal degaussing coil.
14. Turn on the receiver and check the purity by holding one (1)
round magnet at the 3 o'clock and a second round magnet at
9 o'clock position. If purity is not satisfactory, repeat steps 8
through 14.
15. Turn off the receiver and reconnect the internal degaussing
coil.
* Convergence Adjustment
Caution: This procedure DOES NOT apply to bonded yoke and
picture tube assemblies.
Do not use screen magnets during this adjustment
procedure. Use of screen magnets will cause an
incorrect display.
1. Remove AC power and disconnect the internal degaussing
coil.
2. Apply AC Power and set the brightness to the Picture Reset
condition. Set the Color control to minimum.
3. Apply 8V to the pin.
4. Adjust the Red, Green and Blue Bias controls to get a dim
white line.
5. Remove the AC power and 8V from the pin.
6. Reconnect the internal degaussing coil and apply AC power.
7. Turn the receiver on for 10 seconds to perform internal
degaussing and then turn the receiver off again.
8. Unplug the internal degaussing-coil.
9. Turn on the receiver, connect a signal generator to the VHF
antenna terminal and apply a crosshatch signal.
Caution: During the convergence adjustment procedure, be
very careful not to disturb the purity adjustment tabs
are accidentally move, purity should be confirmed
before proceeding with the convergence adjustments.
Note: Make sure the focus is set correctly on this instrument
before proceeding with the following adjustment.
10. Converge the red and blue vertical lines to the green vertical
line at the center of the screen by performing the following
steps (below TABLE).
a. Carefully rotate both tabs of the 4-pole ring magnet
simultaneously in opposite directions from the 12 o'clock
position to converge the red and blue vertical lines.
b. Carefully rotate both tabs of the 6-pole ring magnet
simultaneously in opposite directions form the 12 o'clock
position to converge the red and blue (now purple)
vertical lines with the green vertical line.
11. Converge the red and blue horizontal with the green line at
the center of the screen by performing the following steps.
(below TABLE)
a. Carefully rotate both tabs of the 4-pole ring magnet
simultaneously in the same direction (keep the spacing
between the two tabs the same) to converge the red and
blue horizontal lines.
b. Carefully rotate both tabs of the 6-pole ring magnet
simultaneously in same direction (keep the spacing
between the two tabs the same) to converge the red and
blue (now purple) horizontal lines with the green
horizontal line.
c. Secure the tabs previsouly adjusted by locking them in
place with the locking tabs on the beam bender.
MAGNETS
RED
RED
1.ADJUST YOKE Z-AXIS FIRST
TO GET EQUAL BLUE
COLOR CIRCLES
2 .ADJUST BEAM BENDER 2 POLE
MAGNET TO GET FOUR EQUAL
COLOR CIRCLES
3-4
RING
PAIRS
4
POLE
ROTATION DIRECTION
OF BOTH TABS
OPPOSITE
SAME
OPPOSITE
SAME
MOVEMENT OF RED
AND BLUE BEAMS
B
B
R
R
OR
OR
B
R
B
R
OR
B
R
B
R
B
R
OR
B
R
6
POLE
12. While watching the 6 o'clock positions on the screen, rock the
front of the yoke in a vertical (up/down) direction to converge
the red and blue vertical lines. (Fig upper left)
13. Temporarily place a rubber wedge at the 12 o'clock position
to hold the vertical position or the yoke.
14. Check the 3 o'clock and 9 o'clock areas to confirm that the red
and blue horizontal lines are converged.
If the lines are not converged, slightly offset the vertical tilt of the
yoke (move the rubber wedge if necessary) to equally balance the
convergence error of the horizontal lines at 3 o'clock and 9 o'clock
and the vertical lines at 6 o'clock and 12 o'clock.
15. Place a 1.5 inch piece of glass tape over the rubber foot at
the rear of the 12 o'clock wedge.
16. While watching the 6 o'clock and 12 o'clock areas of the
screen, rock the front of the yoke in the horizontal (left to
right) motion to converge the red and blue horizontal lines.
(Fig. upper right)
17. Temporarily place a rubber wedge at the 5 o'clock and 7
o'clock positions to hold the horizontal position of the yoke.
18. Check the 3 o'clock and 9 o'clock areas to confirm that the
red and blue vertical lines are converged. If the lines are not
converged, slightly offset the horizontal tilt of the yoke (move
the temporary rubber wedges if necessary) to equally
balance the convergence error of the horizontal lines at 6
o'clock and 12 o'clock and the vertical lines at 3 o'clock and 9
o'clock.
19. Using a round magnet confirm purity at the center, right and
left sides and corners. See Purity Adjustment Procedure.
20. Reconfirm convergence and apply a 1.5 inch piece of glass
tape over the rubber foot at the rear of the 5 o'clock and the 7
o'clock wedges.
RED
BLUE
RED
BLUE
BLUE
RED
GREEN
GREEN
BLUE
RED
GREEN
GREEN
ADJUSTMENT
VIEWING
AREA
UP/DOWN ROCKING OF THE YOKE
CAUSES OPPOSITE ROTATION OF RED
AND BLUE RASTERS
ADJUSTMENT
VIEWING
AREA
RED
RED
GREEN
TV
SCREEN
LEET/RIGHT ROCKING OF THE YOKE
CAUSES OPPOSITE SIZE CHANGE OF
THE RED AND BLUE RASTERS
UP/DOWN ROCKING OF THE YOKE
CAUSES OPPOSITE ROTATION OF RED
AND BLUE RASTERS
LEFT/RIGHT ROCKING OF THE YOKE
CAUSES OPPOSITE SIZE CHANGE OF THE
RED AND BLUE RASTERS
DEAD SET
(NO RASTER/NO SOUND)
Check +B voltage at J131
Check the heater elements
of CPT are lighting or not
Check/Replace FR423
Check the voltage at
C430(+)
Check/Replace IC430
R430, IC401, D411, FR422
Check/Replace IC501
Check the voltage
at pin21 of IC501
Check the rectified voltage
of main power at C817(+)
Check/Replace
F801, DB813, R821, T801
Check the voltage
at pin9 of IC802
Check/Replace
D810, ZD810, Q810
Check/Replace
IC802, D806, D811.
Check the secondary
voltage are short
Check/Replace IC01
(IC202, IC01T, IC02T:
in case of with TXT)
0V
0V
150~ 380V
6~ 8V
over 0.4V
8V
No
Yes
0.1V
0.1V
Lower than 6V
112V(or 118V)
Troubleshooting Guide
NO PICTURE/NO SOUND
Check the voltage of
TUNER MB(12V)
Check/Replace
Tuner
Check the tuning
condition
Check the 33V at C416(+)
Check/Replace
R421, ZD404
Check/Replace
FR422, D411, IC401
(RASTER OK)
11.8~ 12.2V
0V
NO RASTER(SOUND OK)
Check heater elements of
CRT are lighting
Check the AC voltage at
H/T pin of CPT SOCKET
on CPT board
Check/Replace
CPT
Check/Replace
FR423, 420
The screen is
blinking
Check replace
IC501
Readjust White
Balance
Check the 180V
line at C418(+)
Check/Replace
D413
Retrace line
is visible
Check the screen voltage (G2)
alignment is correct or not
Check the screen colour
Check the base voltage
of Q901-Q903
Check/Replace
D901~ D903
Check/Replace
R918-920 or
soldering
condition on
CPT board.
No
Yes
Abnormal
White
Abnormal
R/G/B
Normal
12V
4~ 5V
6.0~ 6.5Vrms
0Vrms
NO SOUND(PICTURE OK)
Check the voltage(SMPS 25V)
at pin5 of IC601
Check/Replace of
FR804, D804
Check the soldering
state around IC601
Check/Replace
IC01
Check/Replace IC430
Check/Replace IC601
Check the voltage at
pin16 of IC501
Check/Replace Q508
(TV/AV, TXT switch)
Check the voltage
at pin 10 of IC501
Check the voltage
at pin 5 of IC501
Check whether the
voltage is swing or not at
pin3 of IC01 when turning
the volume up
Check/Replce IC01
Abnormal
Abnormal
Normal(20~ 27V)
10~ 12V
Normal
7~ 9V
0V
NO COLOR
Check the frequency(4.43/3.58MHz)
at pin 34.35 of IC501
Check/Replace
X501, 502
Check/Replace
IC501
Check/Replace
IC01
Check/Replace
IC501
Check/Replace
IC503
Check/Replace
IC502
Check the voltage
of PIN27 of IC501.
Check whether the voltage is swing
or not at the pin5 of IC01 according to
changing colour up/down
Check whether R-Y and B-Y are
out from pin30 and pin31 of IC501
Check whether R-Y and B-Y are
out from pin9 and pin10 of IC503
Check whether R-Y and B-Y are
out from pin11 and pin12 of IC502
Check wheter R/G/B is out from
pin20, pin19 and pin18 of IC501
Check/Replace
IC501
Abnormal
Abnormal
Swing
Swing
Yes
Yes
No
Below 5V
Not
Not
No
No
Normal
NO TELETEXT
Check the voltage 12V at C403(+)
Check the 12V line
to be correct
Check/Replace
IC04T
Check/Replace
Q21T
- Check/Replace
IC01T, IC02T
µ-COM(IC01)
- Check all the connections
of SDA SCL
Check the voltage of
C21T(+)
Check video signal is
normal at the pin3 of
IC01T
Check I
2C Bus (SDA, SCL)
Check/Replace X01T
Abnormal
Abnormal
Normal
4.8~ 5.2V
Yes
Yes
NO
NO
PRINTED CIRCUIT BOARD
STEREO BOARD
