Service Adjustment - Sharp 27K-X2000 Service Manual

27K-X2000

SERVICE ADJUSTMENT

Entering The Fixed Values
1. Before starting all the adjustments, enter the fixed
values listed in Table - A.
Screen Adjustment
1. Feed the B/W pattern signal from the signal generator.
2. Connect the oscilloscope probe between TP854 and
GND.
3. Set the S21 bus data to "01" to get the Y signal mute.
4. Adjust the S16(R), S17(G) and S18(B) settings to
Step "64".
5. Adjust the S12 (SUB-BRIGHT) setting to fix the
voltage between TP854 and GND at 2.15V.
6. Adjust the SCREEN control until the raster becomes
as dim as possible and just visible.
7. Select a luminance-short gun, and adjust the bus data
of S16(R), S17(G) or S18(B) to have the luminance
at the white level.
8. Adjust the SCREEN control again to cut off the CRT.
9. Set the S21 bus data to "00" to deactivate the Y signal
mute.
2.15 ± 0.15 V
White Balance Adjustment
White balance adjustment of composite signal input
1. Feed the B/W pattern signal via the video input
terminal from the signal generator.
2. Adjust the "S19" and "S20" settings to obtain the
specified white level.
White balance adjustment of component signal input
1. Feed the B/W pattern signal via the component signal
input Y terminal from the signal generator.
2. Set the S21 bus data to "01" to get the Y signal mute.
3. Adjust the C08(R), C09(G) and C10(B) settings to
step "64".
4. Select a luminance-short gun, and adjust the bus data
of C08(R), C09(G) or C10(B) to have the luminance
at the white level.
5. Adjust the "C11" and "12" settings to obtain the
specified white level.
DC
GND
10
Sub-Picture Adjustment
1. Receive a good local channel signal through the
antenna B.
2. Make sure the customer picture control is set to
maximum.
3. Enter the service mode and select the service
adjustment "S09".
4. Adjust the data value to achieve normal contrast
range.
5. Receive the same local channel through the antenna
A.
6. Adjust the "A01" setting to achieve the same contrast
as that with the antenna B.
Sub-Tint Adjustment
1. Receive a good local channel through the antenna
B.
2. Set customer tint control to center of it's range.
3. Enter the service mode and select the service
adjustment "S10".
4. Adjust "S10" data value to obtain normal flesh tones.
5. Receive the same local channel through the antenna
A.
6. Adjust the "A02" setting to achieve the same tint as
that with the antenna B.
Sub-Color Adjustment
1. Receive a good local channel.
2. Make sure the customer color control is set to center
position .
3. Enter the service mode and select service adjustment
"S11".
4. Adjust "S11" data value to obtain normal color level.