28JW-74H (serv.man18) - Sharp TV Service Manual (repair manual). Page 12

Three types of contrast levels can be varied as listed below:
• TELETEXT MIX MODE CONTRAST

• TELETEXT CONTRAST

• OSD CONTRAST

Use the volume up/down buttons to adjust to a suitable level, then. It is not necessary to press the stand-by button to store,
data are memorized by exiting the Service Mode.

DVCO Adjustment (PAL)
Carry out the DVCO Adjustment (PAL) as shown below:
1. Receive a Philips pattern signal.
2. While in the DVCO ADJUSTMENT (PAL) menu, press the stand-by button.
3. The adjustment will be carried out automatically and stored.

DVCO Adjustment (NTSC)
No adjustment required.

AGC Adjustment
To correctly align the Automatic Gain Control, follow the procedure outlined below:
1. Tune the set into a pattern generator on CH12.
2. Adjust the signal strength of the pattern generator to 59dB/

µV (75Ω).

3. Enter the Service Mode.
4. Enter the AGC Adjustment menu.
5. Press the stand-by button on the remote control.
6. The adjustment will be carried out and stored automatically.

Auto Installation On/Off
To return the receiver to the original Auto Installation mode, using the volume up or down button, set the Auto Installation
On/Off to On. This setting is automatically stored and when the receiver is turned on the next time it will start up in Auto
Installation mode.

If the TV set does not work and the power indicator  is flashing, follow the sequence according to the information below, as
a guide to fault finding.

1. Unable to read or write into NVM: 66% ON, 33% OFF twice and OFF for a second.

2. MSP failure:  66% ON, 33% OFF for three times and OFF for a second.

3. VCT failure: 66% ON, 33% OFF for four times and OFF for a second.

On        Off

On        Off

On        Off