For adjustment of this model, the bus data is converted to various analogue signals by the Digital to Analogue converter circuit. There are still some analogue adjustments susch as Focus and master Screen voltage.
SERVICE MODE
Before putting the set into service mode, check that customer adjustments are in the normal mode. Use the 'reset' button in the video adjustment menu to ensure customer controls are in their reset position.
SERVICE NUMBER SELECTION
Once in the service mode, press CHANNEL UP or CHANNEL DOWN button on the remote control, or at the set. The service adjustment number will be vary in increments of 'one' from 'S01' to 'P07'. Select it the item you want to adjust.
DATA NUMBER SELECTION
Press VOLUME UP or VOLUME DOWN buttons to adjust the data value to selected item.
TO ENTER SERVICE MODE AND EXIT SERVICE MODE
Unplug the TV from AC mains wall socket.
Simoultaneously press "Volume Up & Channel Up buttons on the TV and Plug In the AC power. Now the TV set is switched ON, and enters the service mode.
To EXIT service mode, turn the television OFF, by pressing the 'Power" button.
Service mode screen display
There will be 3 display items at the top of the screen
- S01 => Service adjustment number
- 55(085) => Data number.
- 02 => Channel
VCO ADJUSTMENT.
- Connect a digital voltmeter between pin number (44) of IC-201 and ground.
- Receive a good local channel.
- Enter the service mode and select the service adjustment "S10".
- Adjust the data, so that the voltmeter reads 2.2V.
- Adjustment is completed.
RF-AGC ADJUSTMENT
- Receive a good local channel.
- Enter service mode, and select service adjustment "S08"
- Set the data value to point where NO noise or beat appears.
- Select another channel to confirm that No noise or beat appears.
Note: You will have to come out of service mode to select another channel. Setting the data value to "00" will produce black raster.
SCREEN ADJUSTMENT
- Receive a good local channel.
- Enter the service mode, and select service adjustment iten [S03], and set the data value here to "00" to set the color level to Minimum.
- Select the service adjustment [S19], and adjust the data value to "01". This will turn OFF the Luminance (Y) signal.[ Y-Mute]
- Select the service adjustment [04], and adjust the data value to "4B".
- Adjust the Master Screen Control, until the raster darkens to the point where raster is barely seen. Do this adjustment in dark enviornment as possible.
- Adjust the service adjustments [S11] Red, [s12] Green and [S13] Blue, to obtain a good grey scale with normal whites,at Low Brightness Level.
- Select the service adjustment [S19], and reset data to "00". Select the service adjustment [S03] and reset the data to obtain normal color level.
- Reset Master Screen Control to obtain normal brightness range.
WHITE BALANCE ADJUSTMENT
- Receive a good local channel.
- Enter service mode and select service adjustment [S03] and set to "00" (minimum color). {Record the original data code under udjustment [S03], beore changing}. [S03] does not have to be adjusted, if you selected a B/W picture or monoscope pattern.
- Alternately adjust the service adjustment data of [S14] and [S15], until a good greay scale with normal whites obtained.
- Select service adjustment [S03], and adjut data to obtain normal color level.
SUB-PICTURE ADJUSTMENT
- Receive a good local channel.
- Make sure that the customer picture control is set to maximum.
- Enter the service mode, and select the service adjustment [S01]
- Adjust data value to achieve normal contrast range.
SUB-TINT ADJUSTMENT
- Receive a good local channel.
- Set customer Tint Control to 'Center' of its range .
- Enter service mode and select service adjustment [02].
- Adjust the data value to obtain normal flesh tone.
SUB-COLOR ADJUSTMENT
- Receive a good local channel.
- Make sure the customer color control is set to center position.
- Enter the service mode, and select service adjustment [S03].
- Adjust [S03] data value to obtain normal color level.
SUB-BRIGHTNESS ADJUSTMENT
- Receive a good local channel.
- Make sure the customer brightness control is set to center position.
- Enter service mode, and select [S04].
- Adjust the data value to obtain normal brightness level
VERTICAL SIZE AND LINEARITY ADJUSTMENT
- Receive a good local channel.
- Enter the service mode and select service adjustment [S09].
- While observing Top and Bottom of the screen, adjust [S09] data value to proper vertical size.
- Using [R502] control, adjsut for best linearity.
VERTICAL PHASE ADJUSTMENT
- Enter the service mode and select service adjustment [S06].
- Adjust the data value to (00).
Note: This must be set to (00), when changed data retrace line will appear.
HORIZONTAL POSITION ADJUSTMENT
- Receive a good local channel.
- Enter service mode and select [S07].
- Adjust the data value so that picture is centered.
CAPTION POSITION ADJUSTMENT [HORIZONTAL]
- Receive a good local channel.
- Enter service mode and select service adjustment [S18].
- A black box appears on the screen.
- Adjust [S18] data value so that text box is positioned in the center of the screen.
3.58MHz TRAP ADJUSTMENT
- Receive a good local channel.
- Enter the service mode and select the service adjustment [S16].
- This is a two position adjustment. "00" is ON and "01" is OFF.
- Adjust the data value to "01" for normal viewing
SHARPNESS AND AUDIO BALANCE ADJUSTMENTS
- Receive a good local channel.
- Enter service mode and select the service adjustment [S05] for sharpness and [S17] for audio balance.
- Sharpness: Adjust the data value to (24) {Center of the data range}, for sharpness adjustment.
- Audio balance: Adjust the data value to (20) {Center of data range}, for audio balance.
VERTICAL CENTER ADJUSTMENT
Receive a good CATV channel
Adjust (S502), so that the picture is centered.
SIDE PINCUSHION ADJUSTMENT
- Receive a good CATV channel.
- Adjust (R676), so that the outer most line on the screen is straight.
HORIZONTAL SIZE ADJUSTMENT
- Receive a good CATV channel.
- Adjust (R678) to best horizontal size.
ENERGY SAVE OFFSET ADJUSTMENT.
- Enter the service mode, and select the service adjustment [S20].
- Adjust the data value to (23)
MTS ADJUSTMENT
- Feed the following monaural signal to pin (14) of IC3001. Monaural signal: 300MHz, 245mVrms
- Connect the rms voltmeter to pin (39) of IC 3001.
- Enter the service mode and select service adjustment [M01]
- Adjust the data so that the rms voltmeter reads : Spec:490 +/- 10mVrms.MT
MTS VCO ADJUSTMENT
- Keep the unit in no signal state.
- Connect the frequency counter to pin number (39) of IC3001.
- Connect a capacitor (100MFD 50V), in between positve side of IC3005 and ground.
- Enter the service mode and select service adjustment [M02].
- Adjust the data so that, the frequency counter reads: Spec: 62.94+/-0.75KHz
FILTER ADJUSTMENT
- Feed the following stereo pilot signal to pin number (14) of IC3001
- Stereo pilot signal 9.4KHz,600mVrms.
- Enter the service mode and select the service adjustment [M03].
- Adjust the data until 'OK' appears in position on the screen. Make sure that the "OK" is displaye almost at the center of the data range.
SEPERATION ADJUSTMENT
- Connect the rms voltmeter to pin number (39) of IC3001.
- Receive the following composite stereo signal: 1 30% modulation, left channel only, noise reduction on 300Hz.
- Enter the service mode and select the service adjustment [M04].
- Adjust the data until, AC voltage reading of the RMS voltmeter is minimum.
- Receive the following composite stereo signal-2. Stereo signal: 30% modulation, Left channel only, noise reduction on 3KHz.
- Enter the service mode and select the service adjustment [M05].
- Adjust the data until, AC voltage reading of the RMS voltmeter is minimum.
- Take the above steps one through 8 again for line adjustment.
P-IN-P Y LEVEL ADJUSTMENT
- Receive a good local channel.
- Enter the service mode and select the service adjustment [P01].
- Adjust data value to obtain normal contrast level.
P-IN-P TINT ADJUSTMENT
- Receive a good local channel
- Enter the service mode and select the service adjustment[P02].
- Adjust the data value to (29).
P-IN-P COLOR ADJUSTMENT
- Receive a good local channel.
- Make sure that the customer color control is at the center position.
- Enter service mode and select service adjustment [P03].
- Adjust the data value to obtain normal color level.
P-IN-P Y-OFF SET ADJUSTMENT
- Receive a good local channel.
- Entter the service mode and select the service adjustment [P04].
- Adjust the data value to (09).
P-IN-P H-POSITION ADJUSTMENT
- Receive a good local channel.
- Enter the service mode and select the service adjustment [P05].
- Adjust the data value to (0A).
P-IN-P BURST GATE PULSE {FOR MAIN}
- Receive a good local channel.
- Enter service mode and select service adjustment [P06].
- Adjust the data value to (00).
P-IN-P FREE RUN
- Receive a good local channel.
- Enter the service mode and select service adjustment [P07]
- Adjust data value to (0B).
