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SAFETY PRECAUTIONS :An isolation transformer should be connected in the power line between the receiver and the AC
line before any service is performed on the receiver.
X- RADIATION PRECAUTION The primary source of X- RADIATION in television receiver is the picture tube. The
picture tube is specially constructed to limit X- RADIATION emission. For continued X- RADIATION protection, the replacement
tube must be the same type as the original including suffix letter. Excessive high voltage may produce potentially hazardous XRADIATION. To avoid such hazards, the high voltage must be maintain within specified limit. Refere to this service manual for
specific high voltage limits. If high voltage exceeds specified limits, take necessary corrective action. Carefully follow the instructions
for + B1 volt power supply adjustment, and high voltage check to maintain the high voltage within the specified limits.
AGC ADJUSTMENT
NOTE; Do not attempt this adjustment with weak signal.
1. Tune receiver to most clearest (or strongest) VHF
station in your area. Set brightness and contrast controls to
maximum. Set colour control to minimum.
2. Set the AGC (VR101 ) control to mid- range.
3. Turn AGC control in direction which causes snow to
appear, then in the opposite direction until the snow just
disappears.
SUB BRIGHTNESS ADJUSTMENT
1. Connect a DC meter between “TP- H“ (positive lead) and
“TP - G“ (negative lead) on main unit.
2. Receive the circular pattern.
3. Set brightness to maximum and contrast to minimum.
4, Adjust sub brightness control (VR211 ) for 0.2V(14) /
0.3V(20) / 0.45V(21 “).
NOTE: If picture tube replaced, check sub-brightness ad-
justment.
VERTICAL SIZE ADJUSTMENT
1. Tune the receiver to monochrome circular pattern.
2. Adjust vertical size (VR451 ) control for full scan.
HORIZONTAL CENTER ADJUSTMENT
1. Tune the receiver to monochrome circular pattern.
2. Set the brightness and contrast to maximum.
3. Adjust video phase (VR411 ) for optimum horizontal center
position.
B1 POWER SUPPLY ADJUSTMENT
1. Connect DC meter to “TP - B“ and ground.
Set the + B1 adjustment control (VR551 ) to mid-range.
2. Set brightness and contrast to minimum.
Tune the receiver to an active channel and synchronize
picture.
3. Adjust+ B1 adjustment control for 130 t 1.0 volt DC.
TUNING DISPLAY WIDTH ADJUSTMENT
1. Receive the monochrome circular pattern.
2. Press the preset switch (SW706).
Tuning bar is displayed on the screen.
3. Adjust VR71 O for optimum tuning bar width.
Press the preset switch, and the tuning bar disappears .
GREY SCALE AND TRACKING ADJUSTMENT
1. Tune the receiver to the monochrome circular pattern.
2, Set the brightness and the contrast to maximum,
the colour to minimum.
3. Set the service switch (SW251 ) at the service side.
4. Set the drive volume (1/R602 and VR612) at their
mechanical center.
5. Set the bias volume (VR601, VR621 and VR611) to
minimum. (fully counter clockwise).
6. Turn the screen volume to obtain just visible one
coloured line.
7. Adjust each bias volume (VR601 - blue, VR621 - green
and VR611 - red) alternately until a dim white line produced.
8. Set the service “switch (SW251 ) at the normal side.
9. Adjust the drive volume (VR602- blue andVR612- red)
alternately to produce normal black and white picture.
10.Check for proper grey scale tracking at all brightness
levels.
NOTE : If grey scale adjustment is made after picture tube
replacement, check high voltage and sub - brightness
adjustment.
COLOUR ADJUSTMENT (PAL)
Receive colour bar pattern. (see Figl on the page2.)
Set the brightness, colour and contrast to maximum.
ADJUST
REMARKS
FOCUS ADJUSTMENT
Adjust focus control on the left side of the chassis for well
scanning lines.
HORIZONTAL WIDTH & HIGH VOLTAGE CHECK
1. Receive the monochrom circular pattern.
2 Set the brightness and contrast to maximum.
.
3. If the picture is too wide or narrow, cut or short the lead
(AJl ) on the main unit. When AJl is shorted, the horiz. width
increase. When AJl is cut, the horiz. width decrease.
4 Connect a high voltage probe to anode lead of the picture
tube.
5. The high voltage must be between 20- 22KV(1 4“) / 23-25
KV (20)/ 24- 26 KV(21 “).
NOTE: If the picture tube is replaced, check the high voltage.
The horiz. width adjustment affects the high voltage
and the sub brightness. Therefore, recheck the sub
brightness and the high voltage.
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