Read Sharp 28KF-84H (serv.man18) Service Manual online
10
28KF-84H
Colour Adjustments
The following adjustments should only be carried out when the CRT, IC850, IC851
or IC852 are replaced.
or IC852 are replaced.
G2 and Cut Off Adjustments
1. Follow the procedure below to set the G2
1.1 Tune the set to the output of a signal generator (cross hatch pattern).
1.2 2. In the user menu, set the picture levels to the FACTORY settings
(normalized).
1.3 Connect the oscilloscope to the RED cathode (pin 8 of CRT socket)
and adjust G2 to read 150V on the sensor pulse as in the drawing:
1.2 2. In the user menu, set the picture levels to the FACTORY settings
(normalized).
1.3 Connect the oscilloscope to the RED cathode (pin 8 of CRT socket)
and adjust G2 to read 150V on the sensor pulse as in the drawing:
Note: Oscilloscope should be adjusted for vertical TV field trigger and synchronized with
video signal.
video signal.
Vertical Bow
Adjust the Vertical Bow so that the picture is centred.
The effect of this adjustment is shown in figure 11.
The effect of this adjustment is shown in figure 11.
•
When the volume up button is pressed, the vertical bow changes to left.
•
When the volume down button is pressed, the vertical bow changes to right.
•
Press the stand-by button on the remote control to store.
Vertical Amplitude
Adjust the Vertical Amplitude so that 8% over-scan is achieved.
The effect of this adjustment is shown in figure 12.
The effect of this adjustment is shown in figure 12.
•
When the volume up button is pressed, the vertical size of the picture increases.
•
When the volume down button is pressed, the vertical size of the picture decreases.
•
Press the stand-by button on the remote control to store.
S Correction
Adjust the S Correction so that the picture symmetrical between the top, centre and bottom.
The effect of this adjustment is shown in figure 13.
The effect of this adjustment is shown in figure 13.
•
When the volume up button is pressed, the top and bottom scanning decreases and the
centre scanning increases.
•
When the volume down button is pressed the top and bottom scanning increases and the
centre scanning decreases.
•
Press the stand-by button on the remote control to store.
Vertical Shift
Adjust the Vertical Shift so that the picture is centred.
The effect of this adjustment is shown in figure 14.
The effect of this adjustment is shown in figure 14.
•
When the volume up button is pressed, the picture moves up.
•
When the volume down button is pressed, the picture moves down.
•
Press the stand-by button on the remote control to store.
Figure 14
Figure 11
Figure 12
Figure 13
150 V
CH1 gnd
Figure 15
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