Adjustment - Sharp 29L-FG1L Service Manual

29L-FG1L

[2] ADJUSTMENT

PIF ADJUSTMENT CHECKING
NO ADJUSTMENT POINT
1 RF-AGC
TAKE OVER POINT
ADJUSTMENT
(I2C BUS CONTROL)
PURITY ADJUSTMENT
NO ADJUSTMENT POINT
1 PURITY ADJ.
(no need this adjutment for
ITC AK MASK CRT type)
2 UNIFORMITY
ADJUSTMENT
(To perform after the
purity and
convergence
adjustment)
ADJUSTMENT CONDITION / PROCEDURE
(1) Receive "US 10CH HALF COLOR BAR" signal.
Signal Strength: 56 ± 1dBµV (75 ohm termination)
Manual Adjustment
(2) Connect the oscilloscope to TP53 (Tuner's AGC Terminal) as shown in figure 3-1.
OSCILLOSCOPE
+
0.1V
1.0V -
+
BIAS BOX
-
Bias Box : about 4.5V
Fig. 3
(3) Select "RF-AGC" item in the Adjustment Mode. Adjust the "RF-AGC"
bus data to obtain the Tuner output pin drop 0.1V
Auto Adjustment
(4) Select "RF-AGC" item in the Adjustment Item. Push the RF-AGC button, blue display with
OK sign indicates the adjustment is working properly.
(5) Change the antenna input signal to 63 ~ 67dBµV, and make sure there is no noise.
(6)Turn up the input signal to 90 ~ 95 dBµB to be sure that there is no cross modulation beat.
ADJUSTMENT CONDITION / PROCEDURE
(1) Select the green monocolor screen with remote contoller, and set the beam current of
900±200µA with the contrast control.
(2) Degauss the CRT enough with the degausing coil.
NOTE: Follow the job instruction manual to adjust the magnetic field.
(3) The purity magnet must be previously set at the 0 magnetic field, and the
convergence must be adjusted to be rough.
With P-MAG, adjust it to the center - rank A.
(4) Observe the points a,b, as shown in Fig.1-1 through the microscope.
Move DY fore and aft to set the landing at the point to be
"inside 20±10µm (for MTPDT)" or "inside 0±10µm (for MTPDM)".
(5) If the a/b balance is poor, compensate it to the center "Rank AB".
(6) Aline it to zero, keeping the raster rotation in the east direction.
(7) Tighten the deflection coil fastening screws.
Tightening torque : 108N ± 20N ( 11Kgf ± 2Kgf )
(8) Checking the CRT corner area, bond the magnetic sheet to set the landing at
rank A for compensation.
Note: Apply the adjustment after aging with the beam current 900±200µA or more
for 30 minutes or more.
Note: Select the service mode, and press the monocolor key of R/C for process,
and the monocolor screen (green) will be selected.
* Every push of the monocolor key, changes the screen as follows.
mono color mono color
WHITE GREEN
SCREEN SCREEN
Monocolor screen
release
Before adjustment begin,Horizontal magnetic field = 0G
Vertical magnetic field = Each destination's adjustment magnetic field
Make sure to degauss it.
(North direction red uniformity)
(1) Horizontal mf = Set to monocolor screen red and adjust to +0.20G.
(2) Pay attention to the edge of CRT,if the landing is poor adjust by attaching the
the compensation magnet at the back of CRT.
(refer to Fig-1)
(South direction red uniformity)
(1) Horizontal mf = Set to monocolor screen red and adjust to -0.20G.
(2) Pay attention to the edge of CRT ,if the landing is poor adjust by attaching the
compensation magnet at the back of CRT.
(The same method is applied for adjustment of monocolor screen blue for
blue uniformity ,and changing both the magnetic field for north and south
direction.)
*During the pasting of compensation magnet , use the crosshatch pattern .
Make sure there is no blur or bendlines occur.
If the blur or bend are serious,adjust the location of compensation magnet
to make it better.
TP51
TV SET
1.0V below maximum voltage.
mono color mono color
BLUE RED
SCREEN SCREEN
3 – 15
WAVEFORM OR REMARKS
Confirmation Voltage : 3.6 ± 0.4 VDC
Monitor point : TP53
WAVEFORM OR REMARKS
a b
90 mm 90mm
Fig. 1 -1
A
A=B
B
Fig 1 -2 . Inside 20±10µm (for MTPDT);
Inside 0±10µm (for MTPDM)
A
A=B
B
Fig 1 -3 . Inside 20±10µm (for MTPDT);
Inside 0±10µm (for MTPDM)
*Continuously press the monocolor key
1 second or more, and the monocolor mode
will be selected without the service mode.
*Even with TEXT key or "R/G/B" key,
it can be directly switched to each monocolor
screen.
(CRT surface)
Mislanding
(CRT back)
compensation magnet
Fig-1