Hitachi P50H401/DW3-U Service Manual page 139

TROUBLESHOOTING THE 42AE1 PANEL:
4.6 PROBLEM ANALYSIS PROCEDURE
4.6.1 "The entire screen does not light (No Picture)" analysis procedure
Disconnect CN68 on PSU, PSU to LOGIC cable
Remove the following power connectors (four locations):
CN 23, CN24(X-SUS), CN 32 (Y-SUS), CN47 (ABUSR)
XSUS
CN22
11
-VS
10
-VS
9
N.C.
8
GND
VCC 7
6
N.C.
5
VA
4
GND
3
N.C.
2
VS
1
VS
CN23
9
-VS
8
N.C.
7
VS
N.C. 6
GND 5
4
GND
3
VCC
2
N.C.
1
Va
The entire screen does not light.
"No Picture"
Main Power Off
Y
Turn on AC power.
Vcc (5V) on PSU board exists?
Y
CN63 pin 1
Turn off AC power
Connect CN68 on PSU
Turn on AC power
Vcc (5V) exists on PSU board?
Y
CN63 pin 1
Turn off the AC power.
On X-SUS board
CN23 (3)-(4) pins or CN23 (5)-(7) pins or
CN22 (8)-(11) pins are shorted?
On XSUS board,
CN63 (1)-(9) pin
Shorted ?
N
(1)
PSU = Power Supply Unit
N
N
Y
Y
Disconnect 6 pcs of XFPC from
CN24, CN62, CN63, CN64, CN65 and CN25
Y
On XSUS board,
CN63 (1)-(9) pin
Shorted ?
On XSUS board,
N
CN63 (1)-(9) pin
XBUS is defective
Panel is
defective
128
PSU board is
defective.
STANDBY power supply
has abnormality.
LOGIC board is
defective.
STANDBY power supply
(MPU power supply) system
has short-circuit.
X-SUS board is
defective.
Switching circuit (power
supply) has a short-circuit.
Remove XBUS U and D
Y
Shorted ?
XSUS is
N
defective
Turn off the AC power,
End of analysis