Sharp SX80J9 Service Manual page 8

PIP (SUB-SCREEN) ADJUSTMENT (on the actual TV set)
3. PIP SUB-TINT ADJUSTMENT (I
1. Receive J-8CH "NTSC colour bar" signal for the
PIP.
2. Connect the oscilloscope to TP803 (PI(2)) on the
main unit.
3. Vary the PIP sub-tint data to get the waveform
as shown in Fig.7 .
4. Clear the adjustment mode.
Note: Note that this waveform is different from that
of the main-screen sub-tint.
SOUND ADJUSTMENT
1. SUB SOUND ADJUSTMENT (I
1. Feed the following signal to the AV terminal.Signal: 1 kHz, 1.76 Vp-p (terminated with a 10-kohm impedance),
0.04/-0.06 Vp-p
2. Set the volume control to MAX.
3. Connect the VTVM probe to the S1 connector. (Pin 1: L-ch, pin 2: GND, pin 3: R-ch)
4. Adjust the sub-sound data so that the VTVM should read the following voltage. For the left channel.
Adjustment error: 7.5 ± 0.1 Vrms
Notes:
• Spatializer off
• In the S-Normal mode
• S-VOL control at MAX position
* Use an 8-ohm dummy load.
2. NOISE MUTE CHECKING
1. Receive E-12CH "PAL colour bar" signal.
2. Turn up the volume control to maximum and make sure the sound is heard from the speakers.Then put the
unit in the no-signal state.
3. Be sure that the sound mute is effective.
4. Finally turn down the volume control minimum.
2 C bus adjustment)
Sub-screen (B-Y)
Adj.
W
Y
Cy G
Mg
R
B
Fig. 7
2 C bus adjustment)
8-1
PURITY ADJUSTMENT
1. Receive the white pattern by pattern generator. Set
the contrast control to have a beam current of 1.9 mA.
2. Fully degauss the cathode ray tube with the degauss-
ing coil.
3. Set the purity magnet to the zero magnetic field, and
roughly adjust the convergence. Now adjust the purity
magnet to get the centering rank A.
4. Move the deflection yoke to and fro, and observe the
points "a" and "b" as shown in Fig. A with a micro-
scope.
Set the landings to 20 µm inside. Insert and drive the
wedge to keep the deflection yoke well balanced top
and bottom.
4. If the points "a" and "b" are poorly balanced, correct
the centering up to the rank AB.
5. Adjust the raster rotation to 0 eastward.
6. Tighten the deflection coil lock screws.Tightening
torque: 108 ± 20 N (11 ± 2 kgf)
7. Check the corners on the cathode ray tube screen.
Correct the landings, as required, to the rank A by ap-
plying the magnetic sheet.
Note: Make this adjustment after warming up the unit
at the beam current of 1900 ± 50 µA for 30 min-
utes or longer.
If any other adjustment is made during the
warming-up, warm up the unit for 2 more min-
utes and start the purity adjustment.
Note: After adjusting the convergence, set the "a"
and "b" landings to 20 µm inside in advance.
SURROUNDING PURITY ADJUSTMENT
1. Make sure the deflection yoke (YPB) is positioned well. Receive the crosshatch signal and move the
deflection yoke to roughly adjust the YH and YV. (Fix the deflection yoke with the wedge within 30 seconds.)
2. Call up the green-only screen, and set the beam current to 1900 µA.
3. Make sure the landings at the corners are of rank A. If not, apply a purity correction magnet and readjust the
landings.
a b
Fig. A
A
B
B
A
Rank "A" (on the Rank "A" (on the
right of the CRT) left of the CRT)
*1: The deflection yoke position (YPB.is adjusted by set-
ting the "a" and "b" landings.
[20-µm inside point]
8-2