NEC LCD1550X Service Manual page 86

2.3 POWER-SAVE Operates (POWER-ON INDICATOR (Orange) is blinking.)
Is sync. signal (or
NO
SCDT) input into
each pin of MPU
IC102?
YES
[Pin no.(#) of MPU IC102 to which sync.
(SCDT) signal is to be input]
Input connector
Hs
Vs
DVI-A CS
S/G-Hs
S/G-Vs
DVI-I
SCDT
Hs
Vs
D-SUB
CS
S/G-Hs
S/G-Vs
MPU may have any problem.
3. Abnormal Picture or Ineffective Adjustment
[A2.5V Line Circuit]
Voltage A2.5V Line Circuit / Schematic Diagram
ASIC
--------
DC2.5V
MAIN
(ASIC)
*A2.5V is generated in IC604 and output from its #8.
Is DC5V (A5V)
output from #6
of IC601?
YES
[A5V Line Circuit]
Voltage
Pin no.(#)
3
DC5V
18
3
2
15
64
(when input DVI-I:HI)
5
20
5
4
17
Is DC3.3V
(TM3.3V)
output from #8
of IC605?
[TM3.3V Line Circuit]
Voltage
DC3.3V
NO
A5V Line Circuit / Schematic Diagram
DDC Circuit Input Interface Input Interface
---------- Circuit Circuit
MAIN(MC) ---------- ----------
MAIN(INPUT) MAIN(SYNC)
NO
TM3.3V Line Circuit / Schematic Diagram
Digital Signal Input Interface
Receiver Circuit Circuit
---------- ----------
MAIN (TMDS) MAIN(INPUT)
4
A5V line may have any problem. Please check the parts below.
MAIN (Power)
A5V generator- IC
MC
DDC circuit- IC
DDC circuit- IC
MC
EEPROM (DDC-DVI)
MC
EEPROM (DDC-DVI)
MC
MC EEPROM (DDC-DSUB)
INPUT S/G (DVI-A)- IC
INPUT S/G (D-SUB)- IC
INPUT Sync-INPUT- IC
Sync INPUT (DVI-A)- IC
Sync
INPUT (D-SUB)- IC
TM3.3V line may have any problem. Please check the
parts below.
TM3.3V generator- IC
MAIN (Power)
Digital signal receiver- IC
TMDS
Please check the part below.
MC MPU
A2.5V line or control circuit may have any problem.
Please check the parts below.
MAIN (Power)
A2.5V generator- IC
ASIC ASIC
MC EEPROM (for adjustment)
MC MPU
IC601
IC106
IC112
IC104
IC105
IC107
IC203
IC202
IC201
IC301
IC304
IC605
IC500
IC102
IC604
IC400
IC100
IC102