21E-FG3RU
PIF ADJUSTMENTPURITY ADJUSTMENT
No. Adjustment pointAdjustment condition/procedureWaveform or othersNo. Adjustment pointAdjustment condition/procedureWaveform or others
1Tuner IFT1. Get the tuner ready to receive the CH. E - 91PURITY ADJ.1. Receive the GREEN-ONLY signal. Adjust the
( PRESET )signal,but with no signal input.beam current to ~700 mA.
Adjust the PLL data.2. Degauss the CRT enough with the degausing coil.
ab
2. Connect the sweep generator's output cable toNote: Follow the Job Instruction Sheet to adjust
10k1n601000p
the tuner antenna. ( RF SWEEP )the magnetic field.
3. Adjust the sweep generator's to 80dBmV.OscilloscopeIF OUTVertical Bv:+0.030 mT (0.30 gauss)
4. Connect the response lead ( use LOW IMPED-100k1000p 75ohmHorizontal Bh: +0.020 mT (0.20 gauss)
ANCE probe with wave detector ; see Fig.1 ) to(Reference: page 7-2)
the tuner's IF output terminal. ( This terminal mustFig.13. Maintain the purity magnet at the zero magneticFig. 1-1
30mm30mm
have the probe alone connected ).field and keep the static convergence roughly
E-9 CH
5. Set the RF AGC to 0 - 6 V with no saturation withadjusted.
the waveform.4. Observe the points a, b as shown in Fig. 1-1
6. Adjust the tuner IF coil to obtain the waveform asP Cthrough the microscope. Adjust the landings to
the A rank requirement.
shown in Fig. 2.-1.5+/-0.8dBA
5. Orient the raster rotation to 0 eastward.
Note: Besure to keep the tuner cover in posi- Fig.26. Tighten up the deflection coil screws.
tion during this adjustment.E Tightening torque: 108 ? 20 N (1?1 2 kgf)B
7. Make sure the CRT corners landing meet the A
rank requirements. If not, stick the magnet sheet
A = B
2RF-AGC1. Receive "PAL COLOUR BAR" signal.* for Auto ADJto correct it.
TAKE OVERE Signal Strength: 56 ? 1 dBmV (75 ohm open)1)Receive OPAL COLOUR BAR�Note: This adjustment must be done after warm-
POINT AD-signal.ing up the unit for 30 minutes or longer withFig. 1-2
JUSTMENT2. Connect the oscilloscope to TP201 (Tunersignal strength: 56 Os AGC? 1dBmV(75a beam current over 700 mA.Rank "A"
2
(IC BUSTerminal) as shown in Fig. 3-1.ohm open)Note:Set the service mode by JA304 & JA307(on the right of the CRT)
CONTROL)1)Go to service mode.(short) then press factory process R/C RGB
Oscilloscope
2)Go to service data V01, presskey to change to RGB mono colour mode.
+TP201
(AUTO &0.1VR/C to operate auto key (Hex* For the following colours press R/C RGB(Hex 7E)
8key to change.
MANUAL ADJ)�C1) and confirm the �OKO
A
display on the screen.
Bias box3)If appear NG, increase dataTV Set
+
some step and pls repeat stepGREENBLUEREDB
2 again.ONLYONLYONLY
�4)proceed step 4 & 5 in manual
E Bias box: About 4.5 VA = B
mode. Signal-colour
screen cleared
Fig. 3-1
Fig. 1-3
3. Call "V01" mode in service mode. Adjust the "V01"
bus data to obtain the Tuner output pin dropRank "A"
(on the left of the CRT)
0.1~1.0V below maximum voltage.
4. Change the antenna input signal to 63~67dBmV,
* Press R/C RGB key for 1 sec-
and make sure there is no noise.
ond in NORMAL MODE, the
5. Turn up the input signal to 90~95 dBmV to be sure
colour will change to RGB
that there is no cross modulation beat.mono colour mode.
8-18-2 |
ACEC
