General Troubleshooting - Samsung CF21M Service Manual

5-2 General Troubleshooting

5-2-1 No Picture
LED blinks?
No
G2 Voltage is right?
Yes
Heater Voltage is right?
Yes
R, G, B Cathode is right?
20
Yes
Check the CRT Socket which
it is connected with CRT.
Replace the CRT.
5-2-2 Shut Down
LED is blinking so fast
(Once per 300m sec)?
No
LED is blinking once a second?
Yes
Check signal cable and signal source.
CF21M*
Yes
Go to 5-2-2 Shut down
troubleshooting guide.
No
Check D598, D599 and G2 wire.
Also check around FBT circuits.
No
Check CN201 Assy and D642, Q672.
No
Return back the No Video (5-1-16)
troubleshooting guide.
Yes
Check SDA (IC201 Pin 30) and SCL
(IC201 Pin 29) Replace IC280, IC201.
5 Troubleshooting
WAVEFORMS
R, G, B, Video
20
5-13