5 Troubleshooting
CF21M*
5-9
5-1-17 No Video
IC101 Pins 2, 4 and 6 (19”: IC105,
Pins 2, 4 and 6) inputs are right?
IC101 Pins 20, 22 and 24
(19”: IC105, Pins 20, 22, 24)
outputs are right?
Check Vcc on IC101 (19”: IC105)
and replace IC101 (19”: IC105).
Yes
Yes
No
Check CN101, IC1, QR51, QG51,
QB51, and IC3 on BNC Board.
No
IC102 Pins 25, 28 and 30
(19”: IC101, 29, 32, 35)
outputs are right?
Check +12 V line.
Check and replace IC102 (19”: IC101).
Yes
No
Are there waveforms at CRT
Socket Pin Red, Green, Blue?
Check +80 V line.
Check and replace IC105
(19”:IC102) and components
around IC105 (19”:IC102).
Yes
No
G2 voltage is right?
Heater Voltage is right?
Check D598, D599 and G2 wire.
Check CN102 wire Assy.
Change CRT.
Yes
Done.
No
Check signal cable and connection.
15
WAVEFORMS
15
CRT Socket, Red, Green, Blue
Summary of Contents for CF21M
Page 7: ...CF21M 6 1 6 Exploded View and Parts List ...
Page 17: ...10 Schematic Diagrams 10 6 CF21M 1 368 V IC601 1 ...
Page 19: ...10 Schematic Diagrams 10 8 CF21M 19 IC103 5 24 15 CRT Socket Red Green Blue 20 R G B Video ...
Page 21: ...10 Schematic Diagrams 10 10 CF21M Memo ...
Page 22: ...Memo 9 Wiring Diagram 9 2 CF21M ...
Page 23: ...Memo 8 Block Diagrams 8 2 CF21M ...
Page 48: ...Memo 7 Electrical Parts List 7 26 CF21M ...
Page 49: ...7 Electrical Parts List CF21M 7 27 Loc No Code No Description Specification Remarks ...
