No Video (Analog) - Samsung 940Fn Service Manual

4 Troubleshooting

4-2 No Video (Analog)

check signal cable connection
and power
Do X401,X901 oscillate
like as figure 1 properly?
1
Yes
Is there R,G,B input at
R11,R106,R108,R117,
R116,R115?
Yes
Do Hsync,Vsync waveformgnal
appear at R147,R830,R142,R145 ?
Yes
Does sync signal(figure 2,3) appear
at Pin 1, pin100 of IC400
Yes
Does sync signal(figure 2,3)
appear at pin43,pin44 of IC200?
Yes
Does the output signal
appear at Pin 17 ~ 20,
22 ~ 27 of CN400?
Yes
Does DC 5V appear at pin
28,29,30 of CN400?
Yes
Replace LCD Panel.
4-2
No
No
No
2 3
No
2 3
No
No
No
Replace or check related circuit
Check input part.
check input part
check IC400 and related circuit
check IC200 and related circuit
check IC 400 and related circuit
check the panel_En signal and
BL_En signal and related circuit