NEC MultiSync FP1350 Service Manual page 77

7-3. OSM Gain Adjustment
1) Receive signal 23.
2) Open Menu (S), TAG7 "OSM COLOR GAIN".
3) Adjust "+", "-" SW so that OSM video amplitude at TP-G on the CRT PWB is set to 31 (±4) Vp-p.
4) Push "EXIT" SW.
7-4. Cut off Adjustment
1) Receive signal 23. All Black
2) Open Menu (S), TAG8 "SUB BIAS" and push "RESET" SW.
Note: Do not touch a front panel key and do not come out from "SUB BIAS" since a picture can not be seen.
3) Connect the DVM with a high voltage probe at TP-G2 on the CRT PWB and adjust SCREEN VR to obtain
700 Vdc ± 5 Vdc. (Use a high voltmeter whose maximum voltage is more than 1.5kV and input resistance
is more than 1000 MΩ.)
4) Set 00 channel x, y, Y modes of color analyzer CA-100 and make sure that the following values are preset.
x = 0.273
y = 0.300
Y = 0.2 cd/m
5) Set analyzer mode at color analyzer.
6) Open Menu (S), TAG8 " SUB BIAS " and adjust until raster appears with "+" and "-" SW . The color that
appears first is the reference color.
Adjust "+","-"SW so that its color analyzer indicated value is 20-80.
If color analyzer does not indicate 20-80, adjust "SUB BIAS" 255 and go to 7).
Then reference color is anything OK.
7) Open Menu (S), TAG8 and adjust the reference color bias so that its analyzer indicated value is 90-110.
8) Open Menu (S), TAG8 and adjust the other color biases so that its analyzer indicated value is 90-110.
9) When the indicated value of the reference color is over 110, repeat steps 7) to 8) so that it is 90-110.
10) Close menu.
Fig 7-1 Wave form of RK, GK, BK
Signal: No.23 (1600*1200@85Hz) All black
Signal: No.23 (1600*1200@85Hz) All black
2
5-36
0
45± Vp-p
1