28JW-74H (serv.man18) - Sharp TV Service Manual (repair manual). Page 7

All adjustments to this chassis, except for focus, are carried out in the 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 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.
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 on the remote control.

••••• To exit the service mode, turn the receiver off using the mains switch.

When the Service Mode is entered the following On Screen Display appears

SERVICE SOFTWARE 

∗∗−∗∗x∗∗

SW on: XXXX   SW off: XXXX   Hours ON: XXXX

The figures displayed in the “XXXX” locations are hexadecimal representations of the number of times that particular
function has been executed. For example if the hexadecimal number displayed after “SW on” was 0E4A, this would
correspond to the receiver being turned on 3658 times.
The figure displayed in the “

∗∗−∗∗x∗∗ ” location is the EPROM version.

The following adjustments can be carried out in the Service Mode.

• Horizontal Shift

• East West Width

• Pin Phase

• Pin Amp (Amplitude)

• Corner Amplitude

• Corner Symmetry

• Vertical Linearity

• Vertical Angle

• Vertical Bow

• Vertical Amplitude

• S Correction

• Vertical Shift

• Red Gain

• Green Gain

Note that the receiver should be set to FULL MODE before carrying out any geometry adjustments. This can be achieved
by pressing the widescreen mode button on the remote control until FULL MODE appears on the OSD. This can only be
done out of the Service Mode.

The following geometry adjustments can be carried out. Detailed instructions on how to execute these are given on the
following pages.

• Blue Gain

• Red Cut Off

• Green Cut Off

• Blue Cut Off

• Alter NVM Pag (Page)

• Alter NVM Pos (Position)

• Alter NVM Val (Value)

• Teletext Mix Mode Contrast

• Teletext Contrast

• OSD Contrast

• DVCO Adjustment (Only PAL)

• DVCO Adjustment (Only NTSC)

• AGC Adjustment

• Auto Installation On/Off