NEC LCD1550X Service Manual page 85

2.2 Back Light Is On (POWER-ON INDICATOR (Green) is blinking).
NO
Does OSD
appear?
YES
Is DC2.5V
NO
(P2.5V) output
from #4 of
[Panel 2.5V Line Circuit]
IC606?
Voltage
DC2.5V
YES
Is sync. Signal
NO
input into each
pin of ASIC
[Pin no.(#) of ASIC IC400 to which sync. signal is to be input]
IC400?
Input Connector
DVI-A
YES
DVI-I
D-SUB
NO
Is DC5V input
into #4 of
IC610?
YES
Is DC5V
NO
(PANEL 5V)
output from #1
of IC610?
YES
Panel 5V line may
have any problem.
[Panel 5V Line Circuit]
Voltage
DC5V
P2.5V Line Circuit/Schematic Diagram
ASIC
-------
MAIN (ASIC)
Pin no.(#)
Hs 148
Vs 149
Hs 155
Vs 154
Hs 146
Vs 147
5V line may have any problem. Please check the parts below.
MAIN (Power)
MAIN (Power)
MAIN (Power)
MAIN (Power)
MAIN (Power)
MAIN (Power)
MAIN (Power)
MAIN (Power)
NO
Control circuit may have any problem. Please check the parts below.
Is Q600 on?
MAIN (Power)
MC
YES
Please check the parts below.
MAIN (Power) PANEL 5V generator- IC
PANEL 5V Line Circuit/Schematic Diagram
Panel Circuit
-------
MAIN (ASIC)
Video circuit may have any problem. Please check the parts below.
ASIC
MC
MC
P2.5V line may have any problem. Please check the parts below.
MAIN (Power)
ASIC
Sync. signal input circuit or ASIC may have any problem. Please
check the parts below.
Sync
Sync
TMDS
ASIC
Video circuit may have any problem. Please check the parts below.
INPUT
INPUT
INPUT
INPUT
TMDS
ASIC
MC
MC
3
DC 12V/5V convertor- Tr
DC 12V/5V convertor- IC
DC 12V/6V convertor- IC
5V OVP- precision resistor
5V OVP- precision resistor
5V OVP- precision resistor
P5V generator- IC
TM3.3V generator- IC
PANEL 5V- ON/OFF- Tr
MPU
ASIC
EEPROM (for adjustment)
MPU
P2.5V generator- IC
ASIC
DVI-A- IC
D-SUB- IC
Digital signal receiver- IC
ASIC
D-SUB-Tr
D-SUB-Tr
DVI-A-Tr
DVI-A-Tr
Digital signal receiver- IC
ASIC
EEPROM (for Adjustment)
MPU
Q601
IC607
IC608
R614
R616
R619
IC610
IC605
Q600
IC102
IC610
LCD panel
IC400
IC100
IC102
IC606
IC400
IC300
IC303
IC500
IC400
Q203
Q205
Q200
Q201
IC500
IC400
IC100
IC102