ADJUSTING THE LCD CIRCUIT
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To
make
this
adjustment,
set
the
backlight switch
to the
“NORMAL”
position.
TL341
VCO free-run
(Wiring board diagram: MAIN Side A)
(Wiring board diagram: MAIN
Side
B)
-J
TL802
/
DAC full-scale
TLEOl
DAC
full-scale
DAC full-scale
COM-amplitude
Adjustment procedure and connecting same as the VCR section.
1. VCO free-run adjustment
t
Test point TL841
Address
VCR ADJ 32
Mode CAM
Procedure
1) Change the VCR ADJ address
93 to DF.
2) Connect the Frequency counter to TL841 and adjust it to the specified with the VCR ADJ address 32.
3) Set the VCR ADJ address 93 to FF.
Note: When the LCD screen disappears during the data setting at the address 93,
keep
changing
the data.
In this case, you can check the address and data by the OSD display of monitor output.
Adjustment 15734kHz f 1OOHz
rating
Examples
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During IC702 (E*PROM) replacement.
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During IC4401
replacement.
2.
DAC full-scale adjustment
TL801 (R OUT), TL802 (G OUT), TL803 (B OUT)
VCR ADJ 3D (R), VCR ADJ 3E (G), VCR ADJ 3F (B)
Test point
Address
Mode
Procedure
CAM
1) Output the picture to the monitor in the CAM mode.
Adjustment
rating
Examples
(While adjusting, no picture appears on the LCD screen. Check the address and data by the OSD display of
monitor output.)
2) Change the VCR ADJ addresses 83, CO and 93 to 00,OO and 77, respectively.
3) Adjust the output voltage of TL801 with the VCR ADJ address 30 and the DC voltage with a digital voltmeter to
the adjustment standard value. At this time, adjust them so that the average of both TP voltage values
corresponds to the standard center value.
4) Adjust the output voltage of TL802rTL803 with the VCR ADJ address 3E/3F and the DC voltage with a digital
voltmeter to the adjustment standard value. (The same as (2))
5) Set all the data of changed addresses to FF.
0.78OVp-p + 1 OmVDC
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During IC702 (E’PROM) replacement.
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During IC4401 replacement.
1 o-9
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