SHARP SX-51J7
Manual de Servicio

SERVICE ADJUSTMENT
No. Adjusting point

PURITY ADJUSTMENT
Adjusting procedure/conditions 1. Receive the GREEN-ONLY signal. Adjust the contrast control to have a beam current of about 700 µA. 2. Degauss the CRT enough with the degausing coil. Note: Follow the Job Instruction Sheet to adjust the magnetic field. Vertical Bv : +0.030 mT (0.30 gauss) Horizontal Bh: +0.020 mT (0.20 gauss) (See page 12.) 3. Maintain the purity magnet at the zero magnetic field and keep the static convergence roughly adjusted. 4. Observe the points �a� and �b� as shown in Fig. 2-1 through the microscope. Adjust the landing to the rank �A� requirements. 5. Adjust the raster rotation to 0 eastward. 6. Tighten up the deflection coil screws. » Tightening torque: 108 ±20 N (11 ±2 kgf) 7. Make sure the CRT corners landing meet the �A� rank requirements. If not, stick the magnet sheet to correct it. Note: This adjustment must be done after warming up the unit for 30 minutes or longer with a beam current over 500 µA 700 µA. Note: Set the service mode by TP1001 and TP1002 (short) then press factory process R/C RGB key to change to RGB mono colour mode. * For the following colours press R/C RGB key to change.
Green-only Blue-only Red-only

Waveform and others

PIF ADJUSTMENT
No. Adjusting point 1 RF-AGC check cut in adjustment (PRESETTED) Adjusting procedure/conditions 1. Receive �PAL COLOUR BAR� signal. » Signal Strength: 54 ± 1 dBµV (75 ohm open) 2. Connect the oscilloscope to TP210 (Tuner�s AGC Terminal) as shown in Fig. 1. Waveform and others Note: For the 50 ohm signal strength gauge, when not using 50/75 impedance adapter, signal strength is 52 ±1 dBµV(75 ohm open), instead of 54 ±1 dBµV (75 ohm open). precaution: The loss of using impedance adapter.

1

Purity adjustment

a

b

Fig. 2-1

Oscilloscope 0.1V + �

TV Set TP210

A

Bias box + �

» Bias box: About 4.5 V

B A=B

Fig. 1

3. Drop Input Signal strength to 51 ±1 dBµV (75 ohm open). 4. Under 1. and 3. conditions, the output voltage should be no change or below +0.1 V. In addition, change input signal strength to 57 ±2 dBµV, the output voltage should be no less than -0.1 V. 5. Change the antenna input signal to 63~67 dBµV, and make sure there is no noise. 6. Turn up the input signal to 90~95 dBµV to be sure that there is no cross modulation beat.

Fig. 2-2 Rank "A" (on the right of the CRT)

7

A

B A=B

Signal-colour screen cleared

Fig. 2-3
Rank "A" (on the left of the CRT)

* Press R/C RGB key for 1 second in NORMAL MODE, the colour will change to RGB mono colour mode. The TEXT Key �R. G. Cy� Key can be directly use to change to other colours screen.

SX-51J7

7-1

7-2