ISAFETY 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 X-
RADIATION. 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 the receiver to the most clearest (or strongest) VHF
station in your area. Set the brightness and the contrast
controls to maximum. Set the colour control to minimum.
2. Set the AGC (VRl 01)control to mid- range.
3. Turn AGC control in direction which causes the snow to
appear, then in the opposite direction until the snow just
disappears.
SUB BRIGHTNESS ADJUSTMENT
1. Connect aDC meter between “TP -H“ (positive lead) and
“TP -G“ (negative lead) on the main unit.
2, Receive the circular pattern.
3. Set the brightness to maximum and the contrast to
minimum.
4. Adjust the sub brightness control (VR211 )for 0.2V.
NOTE: If the picture tube replaced, check the sub-
brightness adjustment.
VERTICAL SIZE ADJUSTMENT
1. Tune the receiver to the monochrome circular pattern.
2. Adjust the vertical size (VR451 )control for full scan.
HORIZONTAL CENTER ADJUSTMENT
1. Tune the receiver to the monochrome circular pattern.
2. Set the brightness and the contrast to maximum.
3. Adjust the video phase (VR411 )for optimum horizontal
center position.
B1 POWER SUPPLY ADJUSTMENT
1. Connect DC meter to “TP -B“ and the ground.
Set the +B1 adjustment control (VR351 )to mid-range.
2, Set the brightness and the contrast to minimum.
Tune the receiver to an active channel and the synchronize
picture.
3. Adjust+ B1 adjustment control for 130 f1.0 volt DC.
TUNING DISPLAY WIDTH ADJUSTMENT
1. Tune the receiver to the monochrome circular pattern.
2. Press and hold the recall button of the remote control unit
for more than 2second.
3. Press”1” button of the channel selector of the remote
control unit, and the tuning bar is displayed on the screen.
4. Adjust VR71 Ofor optimum tunning bar width.
5. Press recall button, and the tuning bar is 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 (VR602 andVR612) 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 adim 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
20LOUR ADJUSTMENT (PAL)
3eceive the colour bar pattern.
jet the brightness, contrast and the colour to maximum,
IADJUST IREMARKS
adjustment.
FOCUS ADJUSTMENT
Adjust the focus control on the left side of the chassis for well
scanning lines.
HIGH VOLTAGE CHECK
1. Tune the receiver to the circular pattern.
2. Set the brightness and the contrast to maximum.
3. Connect ahigh voltage probe to anode lead of the picture
tube.
4. The high voltage must be between 20- 22KV,
NOTE: If the picture tube replaced, check the high voltage.
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