Troubleshooting Procedure In Abnormal Conditions - Samsung HPT5054X/XAA Service Manual

2) Troubleshooting Procedure in Abnormal Conditions

# No Display
& No Display is related with Y-MAIN, X-MAIN, Logic Main and so on.
This page shows you how to check the boards, and the following pages show you how to find the defective board.
[ Y-MAIN ]
Check several points
F5001 for VDD
F5002 for Vs
FUSE
F5004 for VCC
F5005 for OUT_L
OK
Q5009~Q5021
FET/
D5005, D5007
DIODE
D5008
OK
Y-MAIN
Normal State
Samsung Electronics
[ Logic Main ]
LED Blinks Check necessary points
YES
Check the LED
operation
YES NO
Check if internal is
Default Black MICOM operation
Check if any address Check the ASIC
data output is detected Control Signal output
Check if the data
and control signals
between DDR & ASIC
are normal
OPEN
Replace the Board
SHORT
Replace the Board
No Display
[ Y-MAIN ]
Check necessary points
[ Logic Main ]
Check if power is supplied
( 5V, 3.3V )
Check the
power connectivity
Check the FUSE
Check the
Check the
input voltage
If the input voltage is
abnormal, replace the
PSU and check it
again as this indicates
a PSU output error
[ X-MAIN ]
Check several points
F4001 for VCC
F4002 for Vs
F4004 for VDD
F4005 for Ve
Q4002~Q4003
Q4011~Q4016
D4004
D4006~D4008
X-MAIN
Normal State
Troubleshooting
[ X-MAIN ]
NO
OPEN
FUSE Replace the Board
OK
SHORT
FET/
Replace the Board
DIODE
OK
4-9