Dpms Failure - Samsung CF21M Service Manual

5 Troubleshooting
5-1-2 PFC Failure
Check the Voltage at IC701 Pin5.
The Voltage is around 10V
Yes
Q701 Gate waveform is right?
1
Yes
Check the Voltage at D701 cathode.
The Voltage is about 400V
Yes
Done.

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)
Yes
Does +14V_V Line off?
(Check the Q670 Collector)
Yes
Does the Q620 activate?
Yes
Done.
5-2
No
?
DC
No
No
?
DC
No
No
No
Check and Replace D702,
R711, ZD705, ZD706.
Replace IC701.
Replace Q701, D701.
Check IC201 Pin 25
or replace IC201.
Check Q671, D670.
Check IC201 Pin 23
or replace IC201.
WAVEFORMS
368 V (IC601, #1)
1
CF21M*