SERVICE MODE
- The following display comes on the screen by pressing DISPLAY key and VSM key at the same time.
SERVICE MODE
- Then, press CURSOR UP OR DOWN key to be in Service menu.
- To select Service Menu parameters use CURSOR UP OR DOWN key and to adjust these parameters use CURSOR LEFT OR RIGHT key.
- To get H-line press VSM and DISPLAY Simultaneously.
- Press CURSOR UP KEY to get R CUTOFF.
- Press '0' to get H-line.
- To come out of H-line again press '0'.
There are FOUR VSM PRESETS.(CARTOON,FILM/POP,NEWS,)
For the setting of individual VSM PRESETS
- Press VSM and DISPLAY at the same time.
- Press CURSOR DOWN key to get the Setting for the VSM PRESET.
- Press CURSOR DOWN key for the selection of each parameter.
- Use CURSOR LEFT/RIGHT key for their setting as per the table given below.
- Press VSM Key for selection of VSM PRESETS.
CLICK ON TABLES TO ZOOM
VCO Adjustment- Switch ON the TV Set.
- Select colour bar pattern {carrier frequency of 38.9MHz} from pattern generator.
- Connect this signal to the input of Saw Filter(after disconnecting IF output of Tuner)
- Connect Digital Multimeter to AFC out(pin no. 2 of VCD IC52771, IC201)
- Adjust VCO coil in such a way that Digital Multimeter shows 4V(sudden change in voltage reading from8V). This voltage should be adjusted whenever there is sudden fall from8V to 1V.
# Correct AFT
voltage alignment can be confirmed by monitoring proper wave format pin no. 38
of VCDIC 52771 IC no. 201./CRO can be also connected to Video OUT terminal.
Low light Adjustment
Warm up the receiver for more than 30 minutes.
- Receive the monoscope pattern signal .
- Select either R CUTOFF , G CUTOFF B CUTOFF in the Service menu.
- Push 0 key on any mode to make a horizontal line.
- Turn the screen knob (the Bottom of FBT) gradually from fully left to the right & search for the first appearing colour.
- Adjust two colours except for the first colour which appears by the adjustment 5) to the white colour with the following 1~ 6 key.
- Turn the screen knob so that a horizontal line appear slightly.
- Change the normal screen by pushing 0 key again.
- Receive the pedestal pattern signal
- Readjust the Colour of the pattern to white colour by varying 1~ 6
Warm up the receiver for more than 30 minutes.
The low light adjustment should be done in advance.
- Receive the monoscope pattern signal .
- Select R-DRIVE &/OR B DRIVE in the Service Menu.
- Adjust R-DRIVE& B-DRIVE so that the white balance is at the directed value (Adjustment point “A”).
- Check if the tracking of white balance from Low light till High light is good.
- Receive the pedestal pattern signal .
- Check if the white balance of low light is good. If the white balance of the low light is not good, adjust the low light again.
- Receive the monoscope pattern signal. Repeat step (4) onwards till perfect white balance is achieved in low light and high light patterns.
- Receive the Black pedestal pattern signal .
- Select Sub Bright in the Service Menu.
- Adjust the Sub Bright so that the point of below table gradation value does not shine.
Contrast Adjustment
- Receive the Black pedestal pattern signal.
- Connect the probe of the oscilloscope to green cathode.
- Select Sub Contrast in the Service Menu.
- Adjust it so that the value between the dot line & white peak of the signal waveform as mentioned below to be the directed voltage as mentioned in the Table below.
Note : While entering in Service Menu ,by
default it takes the values of VSM-cartoon, hence the above parameter is
adjusted with respect to cartoon condition.
Colour Adjustment (PAL)- Receive the PAL colour bar pattern signal .
- Connect the probe of the oscilloscope to green cathode.
- Select Sub color in the Service Menu.
- Adjust the Sub color so that the value between the white peak & blue as per below table.
Colour Tint Adjustment (NTSC3.58,NTSC4.43)
- Connect the NTSC Video Colour bar pattern signal (White 75%) to Video input Terminal.
- Connect the probe of the oscilloscope to BLUE CATHODE.
- Adjust the Sub Tint so that the value between the white peak and Magenta is as per the table shown below.
Note: While entering in the SERVICE MENU by
default it takes the value of VSM cartoon, hence the above parameter is
adjusted with respect to cartoon condition.