SHARP CX48K4
Manual de Servicio

HORIZONTAL AND VERTICAL DEFLECTION LOOP NTSC CHROMA ADJUSTMENT
SAME LEVEL

NO. Adjustment part Adjusting procedure conditions Waveform and others

V-LINEARITY Monoscope Pattern Signal. 1 SUB-TINT 1. Receive the "NTSC3.58 Colour Bar" signal

2

2. Call the "V-LIN" mode. (I C BUS through AV in.

3. Increase or decrease "V-LIN" by Volume key till CONTROL) 2. Connect the oscilloscope to TP853 (Pin (5) of » Sweep time : 10 µsec/div.

horizontal line in the center of monoscope is P882) BLUE-OUT. just at position where the blanking starts. » Range : 100mV/div. (AC)(Use Probe 10:1)

2 V-CENTER 1. Call the "V-CENT" mode.

2

(I C BUS 2. Increase or decrease "V-CENT" by Volume key 3. Call the "SUB-TINT" mode in service mode. waveform shown as Fig. 9.

CONTROL) till picture is centered. Adjust "SUB-TINT" bus data to obtain the W Y Cy G Mg R B

3 V AMP 1. Call "V-AMP" 4. Clear the SERVICE mode. Fig. 9

2

(I C BUS 2. Increase or decrease "VAMP" by Volume key

CONTROL) to set overscan of 9.5% typical.

Adjustment Spec 9.5% range +1% -0%.

4 S-CORRECFIXED DATA, NO NEED TO ADJUST.

PROTECTOR OPERATION CHECKING
PROTECTOR 2. Set CONTRAST MAX. each short test. 3. Set BRIGHT MAX. 5 H CENTER 1. Call the "H-CENT" mode. 4. During the Collector & Emitter of Q883/5/7 2. Increase or decrease "H-CENT" by Volume key short, make sure the protector ON and switch to center the picture horizontal. to standby mode.

NO. Adjustment part Adjusting procedure conditions Waveform and others BUS CONTROL) 1 BEAM 1. Receive "Monoscope Pattern" signal. * Select one of Q883/5/7 to do

2

TION (I C

6 SUB1. Call the "SUB-SHP" mode.

SHARPNESS 2. Set "SUB-SHP" to 20 by pressing Volume down 2 H, V 1. Receive "Monoscope Pattern" signal.

key. PROTECTOR 2. Connect output of Bias Box to D607 cathode (R606 side). 3. Set voltage of Bias Box to 18V and make sure protector is not work. 7 Focus 1. Receive the "Monoscope Pattern" signal.

9
3 Other 1. Once finish rectified Electrolytic Capacitor short protectors testing in +B line, check all possible damaged
Cy G B NO. Adjustment part Adjusting procedure conditions Waveform and others

adjustment 2. Press R/C set Picture NORMAL condition. 4. Set voltage of Bias Box to 27V, and make sure

3. Adjust focus control to get best focus. the protector is work.

components on +B line.

(Use random selected set for inspection)

PAL CHROMA ADJUSTMENT

NO. Adjustment part Adjusting procedure conditions Waveform and others

1 SUB COLOUR 1. Receive the "PAL Colour Bar" signal.

2

(I C BUS 2. Press R/C to set Picture Normal condition. (C881 and R885). AUDIO OUTWhite Color Bar, Sound 400 Hz 100% Mod.) » Sweep time : 10 µsec/div. PUT CHECK 2. Terminate the Video output with a 75 ohm im-

CONTROL) 3. Connect the oscilloscope to Red cathode

CHECKINGOUTPUTANDINPUTA/V

» Range : 20 V/div. (AC) (Use 10:1 probe) 1 VIDEO AND 1. Receive the "PAL Colour Bar" signal (100%

4. Using R/C call "SUB COL" in SERVICE pedance. Make sure the output is as specified

mode. Adjust SUB COLOUR bus data, so that (1.0 Vp-p ±3 dB). 75% White & Red portions of PAL Colour W Y 100%W Mg R 3. Terminate the Audio output with a 10k ohm imBar be at same level shown Fig. 8. 75% pedance. Make sure the output is as specified

5. Clear the SERVICE mode. (1.76 Vp-p ±3 dB). Fig. 8 2 VIDEO AND 1. Using TV/AV key on the remote controller, AUDIO INPUT make sure that the modes change in order of CHECK TV, AV1, AV2 TV again and the video & audio output are according to the input terminal for each mode.

CX48K4

9-1 9-2