Samsung DP14LS Service Manual page 34

Symptoms 2: – X-ray protection
– One vertical line and then high voltage shut down.
Are C417, C504, D502, D503, R509
and R510 ok?
Yes
Check and replace D407, D408,
D414, Q402, Q504, IC401.
Check and replace IC201.
2
6-2-13 I C Failure
– Almost data (Horizontal drive duty, FBT B+ duty, display image data, color data) is transferred
from IC201 to IC203 and IC401 through I
– After user adjusts display image data, contrast and brightness data, these are saved to IC203.
Key check (6-2-18)
Is 5 V on IC401's Pin 32 and
IC203's Pin 8?
Yes
Is there data communication on
14
IC401's Pins 30 and 31?
Yes
Is there data communication
on IC401's Pins 30 and 31 during
14
I 2 C function? (H/V Posi, V_Size,
S_Pin, Trap, Cont, Bright)
Yes
Done
DP14L*/DP15L*
No
Check and replace it.
2
C data line during power on.
No
Check and replace it.
No
No
2
Check I C data and clock line.
Check and replace I
(IC201, IC203, IC401)
2
C devices.
6 Troubleshooting
WAVEFORMS
14 5.92 V (IC203, #5, 6)
CH1 P-P = 5.92 V CH1 RMS = 3.812 V
CH1 : IC401's Pin 31
CH2 : IC401's Pin 30
6-15