PDP-5050SX
142
1
2
3
4
1
2
3
4
C
D
F
A
B
E
7.1.7 TROUBLESHOOTING
Symptom
Defective Assy
Possible Cause
Check Point
Possible
Defective Part
Remarks
No power (both red and green LEDs unlit)
Cable disconnection
CN4204
Check if the connection between the PANEL POWER SUPPLY and
DIGITAL VIDEO assemblies is properly made.
While the red LED remains lit, the green
LED begins flashing (200 ms).
No backup copy
Key input not effective
Cable disconnection
CN4801 - CN4851
ADD1225
Check if the FPCs are properly connected. Check if imparting
vibration to the unit affects key inputs. Check if a pulse is output
when the key corresponding to Pin 2 of the CN4852 is pressed.
The backup copy process was not performed when the Digital Assy
was replaced. (See "7.1.6 Backup when the main unit is adjusted".)
Cable disconnection
CN4852 - CN8656
Check if the cables are disconnected or not securely connected.
Check if a pulse is output when the key corresponding to Pin 6 of
the CN8656 is pressed.
KEY CONTROL
Defective KEY SCAN IC
KEY CONTROL Assy
IC4851
Check if a pulse is output when the key corresponding to Pin 2 of
the CN4852 is pressed.
Remote control unit not effective
Cable disconnection
CN4901 - CN8656
CN9461 - CN8656
Check if the cables are not connected or securely connected.
Check if the cables are not connected or securely connected.
PANEL IR
Defective infrared receiver
PANEL IR
U4901
Check if a pulse is output when the key corresponding to Pin 3 of
the CN4901 is pressed.
Abnormality in a one-eighth area of the
screen
Both red and green/orange LEDs unlit
DIGITAL VIDEO
Defective IC4
Cable disconnection
IC4 BLOCK
IC5401
Check if an abnormal area in the screen changes when the FPC
connected to the address corresponding to the abnormal area is
replaced with the one corresponding to the next address.
ADDRESS
Check that an abnormal area in the screen does not change when
the FPC connected to the address corresponding to the abnormal
area is replaced with the one corresponding to the next address.
[ Diagnosis of abnormalities other than shutdown and power-down ]
