Sony KV21LT1B FD Trinitron CRT TV – service mode, circuit adjustments and schematic diagram

 

KV-21LT1B RM-887 French SCC-Q54C-A, KV-21LT1E RM-887 Spanish SCC-Q53C-A, KV-21LT1K RM-887 OIRT SCC-Q51C-A, KV-21LT1U RM-887 UK SCC-Q52C-A, KV-21FT2K RM-887 OIRT SCC-Q51E-A

The identification of errors within the FE-2 chassis is triggered in one of two ways :- 1: Busy or 2: Device failure to respond to IIC. In the event of one of these situations arising the software will first try to release the bus if busy (Failure to do so will report with a continuous flashing LED) and then communicate with each device in turn to establish if a device is faulty. If a device is found to be faulty the relevant device number will be displayed through the LED (Series of flashes which must be counted) See table 1., non fatal errors are reported using this method.  Each time the software detects an error it is stored within the NVM. See Table 2.

How to enter into Table 2

1. Turn on the main power switch of the TV set and enter into the ‘Standby Mode’.
2. Press the following sequence of buttons on the Remote Commander.

CIRCUIT ADJUSTMENTS

Service adjustments to this model can be performed using the supplied Remote Commander RM-887.

How to enter into the Service Mode

1. Turn on the main power switch and enter into the stand-by mode.
2. Press the following sequence of buttons on the Remote Commander.

‘TT—’ will appear in the upper right corner of the screen.  Other status information will also be displayed.

3. Press ‘MENU’ on the remote commander to obtain the following menu on the screen.

4. Move to the corresponding adjustment item using the up or down arrow buttons on the Remote Commander.
5. Press the right arrow button to enter into the required menu item.
6. Press the ‘Menu’ button on the Remote Commander to quit the Service Mode when all adjustments have been completed.

Note
• Before performing any adjustments ensure that the correct model has been selected in the ‘Model Setting’ menu.
• After carrying out the service adjustments, to prevent the customer accessing the ‘Service Menu’ switch the TV set OFF and then ON.

Sub Brightness Adjustment

1. Input a Monoscope pattern.
2. Press ‘TEST’ ‘TEST’ 13 on the Remote Commander.
3. Adjust the ‘Sub-Brightness’ data so that there is barely a difference between the 0 IRE and 10 IRE signal levels.

Sub Contrast Adjustment

1. Input a video signal that contains a small 100% white area on a black background.
2. Connect an digital voltmeter to Pin 10 of J701 [C Board].
3. Adjust the Sub-Contrast [‘TT11’] to obtain a voltage of 95 +0,- 5V

Sub Color Adjustment

1. Receive a PAL color bar signal.
2. Connect an oscilloscope to Pin 3 of CN504 [A Board].
3. Enter into the ‘Service’ service menu.
4. Adjust the ‘Sub Color’ data so that the Cyan, Magenta and Blue color bars are of equal levels as indicated below.
Note:
Ensure that no signal is applied to the Antenna socket while carrying out the following IF adjustments.

Tuner AGC Adjustment

1. Set the “AGC adjust” register value: 

• For destination France set the value to 6.
• All other destinations set the value to 0

2. Receive a signal of 64dBuV / 75 ohm terminated [62dBuV / 75 ohms for B model] via the tuner antenna socket.
3. Connect a voltmeter to pin1 of TU101 [print side of A Board] or to the AGC pin of CN001 [mount side of A Board].
4. Confirm that the AGC voltage is 3.5volts +/- 0.3volts.
5. If adjustment is required, enter into the ‘Test Menu’.
6. Select the ‘AGC Adjust’ menu item.
7. Adjust the data using the left and right arrow buttons on the Remote Commander to obtain a voltage of 3.5V +/- 0.3V

Deflection System Adjustment

1. Enter into the ‘Geometry’ service menu.
2. Select and adjust each item in order to obtain the optimum image.

TEST MODE 2:

Is available by pressing the ‘TEST’ button twice, OSD ‘TT’ appears.
The functions described below are available by selecting the two numbers. To release the ‘Test mode 2’, press 00, 10, 20 ... twice or switch the TV set into Stand-by mode. In ‘TT Menu’ mode, it is possible to remove the Menu from the screen by pressing the Speaker Off button once. Pressing the Speaker OFF button a second time will cause the Menu to reappear. The function is kept even when the menu is not displayed on screen.

PWB & Circuit diagrams