Samsung DP14LT, Service Manual

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6 Troubleshooting
DP14L*/DP15L* 6-13
6-2-10 Vertical Deflection Failure
Are +13 V, –12 V line OK?
Is V_out waveform on IC401’s
Pin 23?
Yes
Check and replace D608, D609,
IC301, IC302.
No
Symptoms: – One horizontal line
– Rainbow color, No Video
Check and replace
R307, R308, IC401.
No
Is V_deflection waveform on
IC301’s Pin 6?
Check and replace IC301, R305, R306,
and some parts around it.
Check and replace IC401.
Yes
Is 8 V on IC401’s Pin 21?
No
Yes
No
Yes
Refer to 6-2-13 I
2
C Failure.
10
9
6-2-11 Invariable V_Size or V_Position
Key check (6-2-18)
Refer to 6-2-13 I
2
C Failure.
Does V_Out (IC401’s Pin 23) vary,
pressing V_Size or V_Posi key?
Check and replace IC301 and some
parts around it.
No
Yes
WAVEFORMS
10 50.8 V (IC301, #6)
CH1 P-P = 50.8 V CH1 RMS = 7.04 V
9 3.16 V (IC401, #23)
CH1 P-P = 3.16 V CH1 RMS = 3.686 V
9
WAVEFORMS
9 3.16 V (IC401, #23)
CH1 P-P = 3.16 V CH1 RMS = 3.686 V