Samsung DP14LT, Service Manual

Page: 34 / 78

6 Troubleshooting
DP14L*/DP15L* 6-15
Are C417, C504, D502, D503, R509
and R510 ok?
Yes
Check and replace it.
No
Symptoms 2: – X-ray protection
– One vertical line and then high voltage shut down.
Check and replace D407, D408,
D414, Q402, Q504, IC401.
Check and replace IC201.
Is 5 V on IC401’s Pin 32 and
IC203’s Pin 8?
Check and replace it.
No
Yes
Is there data communication on
IC401’s Pins 30 and 31?
No
Yes
Is there data communication
on IC401’s Pins 30 and 31 during
I 2 C function? (H/V Posi, V_Size,
S_Pin, Trap, Cont, Bright)
Check I
2
C data and clock line.
Check and replace I
2
C devices.
(IC201, IC203, IC401)
No
Yes
Done
14
14
6-2-13 I
2
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
2
C data line during power on.
– After user adjusts display image data, contrast and brightness data, these are saved to IC203.
Key check (6-2-18)
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