Sharp 27SC26BQ, Service Manual

Page: 13 / 42

13
SERVICE ADJUSTMENT
H-VCO ADJ (I 2 C BUS CONTROL) (Auto &
Manual Adj)
•
Manual Adj.
1. In No Signal (RASTER) condition.
2. Go to service mode, choose service data V87.
3. Connect oscilloscope to IC801 Pin15, adjust V87 until
frequency become 15.75±0.15kHz.
•
Auto Adj.
4. In No Signal (RASTER) condition.
5. Go to service mode, choose service data V87, by
pressing R/C Auto (HEX 44) key, OSD will appear
"OK" at screen.
6. If appear "NG", please repeat step 3.
VIF-VCO ADJ (I
2
C BUS CONTROL) (Auto &
Manual Adj)
•
Manual Adj.
1. In No Signal (RASTER) condition.
2. Go to service mode, choose service data V86.
3. Connect oscilloscope to IC801 Pin9, adjust V86 until
voltage between 2.5±1.0V.
•
Auto Adj.
4. In No Signal (RASTER) condition.
5. Go to service mode, choose service data V86.
6. Press the R/C Auto (HEX C5) key, OSD will appear
"OK" at screen.
7. If appear "NG", please repeat step 3.
RF AGC Adjustment
1. Receive a good local channel.
2. Enter the service mode and select the service
adjustment "V82".
3. Set the data value to point where no noise or beat
appears.
4. Select another channel to confirm that no noise or
beat appears.
Note 1 : You will have to come out of the service
mode to select another channel.
Note 2 : Setting the data to "00" will produce a black
raster.
Screen Adjustment
1. Receive a good local channel.
2. Enter the service mode and select the service
adjustment "V03" and set the data value to "00" to
set the color level to minimum. (Record original data
code under adjustment "V03" before changing) You
may skip this step, if you selected a B/W picture or
monoscope pattern.
3. Select the service adjustment "V95" and adjust the
data value to "02", this turn off the luminance signal
(Y-mute).
4. Adjust the master screen control until the raster
darkness to the point where raster is barely seen.
5. Adjust the service adjustments "V06" red, "V07" green
and "V08" blue to obtain a good grey scale with
normal whites at low brightness level.
6. Select the service adjustment "V95" and reset data
to "00". Select the service adjustment "V03" and reset
data to obtain normal color level.
7. For component input, the data value of "V16" red,
"V17" green and "V18" blue is adjusted to follow the
data value of "V06", "V07" and "V08" respectively.
8. For digital RF input, the data value of "V26" red, "V27"
green and "V28" blue is adjusted to follow the data
value of "V06", "V07" and "V08" respectively.
9. Reset the master screen control to obtain normal
brightness range.
NECESSARY UNNECESSARY
ADJUSTMENT
PART REPLACED
IC801
The adjustment is needed to compensate for characteristics of parts
including IC801 and MTS level (M01).
Holding down both the VOL-up and CH-up buttons on the TV set at service mode for more than 2 seconds will
automatically write the above initial values into IC2101.
NOTES
X
IC2101
IC3001
CRT
Holding down both the VOL-up and CH-up buttons on the TV set in
the service mode for more than 2 seconds will automatically write the
above initial values into IC2101 Then perform a complete adjustment.
Adjust items related to picture tube only.
Adjust items related to MTS only (M01~M07).
X
X
X
27SC26BQ