5 Troubleshooting
5-14
720C/920C
5-2-3 Missing Color
Are proper Video levels
on CN101 (D-Sub) Pins 1, 2 and 3
?
Are proper AC voltage on all
cathodes?
Refer to 5-1-16 No Video.
Yes
Yes
No
Check signal generator and cathode.
No
Are proper DC voltage on all
cathodes?
Check IC104 (17”: IC104 Pins 19, 20,
and 21) Pins 10, 11 and 12.
Check QB02, QB03, QG02, QG03
QR02 and QR03.
Change the CRT.
Done
Yes
No
Is G2 voltage right?
Check G2 wire, G2 control, volume
and FBT.
Yes
No
Summary of Contents for 720C
Page 33: ...720C 920C 6 1 6 1 720C Exploded View and Parts List ...
Page 34: ...720C 920C 6 2 6 2 920C Exploded View and Parts Lists ...
Page 80: ...R299 720C 920C 10 2 10 2 MICOM Parts Schematic Diagram ...
Page 81: ...720C 920C 10 3 10 3 Horizontal Vertical Processor Parts Schematic Diagram R265 C272 R262 ...
Page 83: ...R561 R562 R501 C530 L521 R523 R526 720C 920C 10 5 10 5 High Voltage Parts Schematic Diagram ...
Page 84: ...720C 10 6 1 10 6 1 720C Video Parts Schematic Diagram ...