Service manual

CF21M* 5-1
5 Troubleshooting
5-1 Parts Level Troubleshooting
Notes: 1. If a picture does not appear, Click the Brightness and Contrast button on the front panel, and then increase the value
of Brightness and Contrast.
2. Check the following circuits.
• No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit.
• High voltage develops but no raster appears: Video output circuits.
• High voltage does not develop: Horizontal output circuits.
5-1-1 No Power Supply
Check and replace FG601, D601,
D701, Q701, IC601 and ZD601.
Done.
IC601 Pin 1 waveform is right?
Check and replace
IC601, ZD601, D606, IC701.
Check and Micom. (IC201)
•
Check and replace IC651.
•
Check every IC connected to 12V.
Yes
No
Check the Voltage at
C607 plus polarity point.
Is the Voltage 400VDC?
with PFC : 400VDC
without PFC : it is different
according to input voltage
Check and replace
FG601, D601, D703.
Yes
No
The secondary voltage of
T601 is right?
(Is it same the schemetic diagram)
Check TR, IC and biode
related to every B
+
line.
Yes
No
•
Check IC651 (KA78R12) Pin 12?
•
Is the voltage 12VDC?
Appear 4VDC Pin 4 of IC651?
Yes
No
No
Yes