5 Troubleshooting
5-2
CF21M*
5-1-2 PFC Failure
Check the Voltage at IC701 Pin5.
The Voltage is around 10V
DC
?
Check and Replace D702,
R711, ZD705, ZD706.
Yes
No
Q701 Gate waveform is right?
Replace IC701.
Yes
No
Check the Voltage at D701 cathode.
The Voltage is about 400V
DC
?
Replace Q701, D701.
Yes
No
Done.
1
5-1-3 DPMS Failure
Check signal source
H/V sync. video signal.
Make No H/V sync.
( That is power off mode).
LED blinks?
Does +12V Line off?
(Check the IC651 output Pin 2)
Check IC201 Pin 25
or replace IC201.
Yes
No
Does +14V_V Line off?
(Check the Q670 Collector)
Check Q671, D670.
Yes
No
Does the Q620 activate?
Check IC201 Pin 23
or replace IC201.
Yes
No
Done.
WAVEFORMS
1
368 V (IC601, #1)
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 ...
