Sharp 28JW-76E, Service Manual

Page: 7 / 88

7
28JW-76E
ADJUSTMENT PROCEDURES
All adjustments to this chassis, except for focus, are carried out in the Service Mode.
••••• SERVICE MODE
The Service Mode is provided to enable the engineer to correctly set up the receiver to the CRT fitted in the set.
Note that the value of these adjustments may vary from one receiver to another.
To enter the Service Mode, carry out the following procedure.
1. Connect a test pattern to the antenna terminal.
2. Tune the receiver to this signal.
3. Turn the receiver off using the mains switch.
4. Press volume down and channel up buttons on the
front of the receiver at the same time.
5. Keeping these buttons pressed, turn the mains on.
6. When the set starts up it will be in Service Mode, then the following
On Screen Display appears:
7. Release the two buttons.
••••• Use the channel up and down buttons to move between the options.
••••• Use the volume control buttons to change the data.
••••• To store the data: use the Stand-by button(1) or Store button(11) on the remote control.
••••• To exit the Service Mode, turn the receiver off using the Main switch.
Note: In this Service Mode, by using the colour buttons of Remote Control is possible to pass directly to the adjustments
that are indicated
inside of each coloured box (see Figure 2), as follows.
Press the RED button to access to Geometry adjustments.
Press the GREEN button to access to NVM adjustments.
Press the YELLOW button to access to Automatic Gain Control adjustments.
Press the BLUE button to access to CUT OFF adjustments.
Adjustment menu:
The following adjustments can be carried out in the Service Mode.
Figure 1
Figure 2
•
Horizontal shift
•
Horizontal size
•
Pin phase
•
Pin amplitude
•
Upper corner correction
•
Lower corner correction
•
Extreme corner correction
•
Vertical linearity
•
Vertical angle
•
Vertical bow
•
Vertical size
•
Vertical S-correction
•
Vertical shift
•
Cut RED
•
Cut GREEN
•
Cut BLUE
•
Hot Cut RED
•
Hot Cut GREEN
•
Hot Cut BLUE
•
Cold Cut RED
•
Cold Cut GREEN
•
Cold Cut BLUE
•
Automatic Gain Control
•
Subcarrier adjustment (ONLY PAL)
•
NVM PAGE
•
NVM POSITION
•
NVM VALUE
RED
GREEN
YELLOW
BLUE
CH
4
5