Trouble Shooting - Pioneer DV-490V-S Service Manual

1

7.1.6 TROUBLE SHOOTING

No. Symptoms
The power is not turned on. Check the voltage of AT+3.3V, –28V and FLDC on the POWER
1
A
B
2 An opening screen is not
displayed on the monitor
(The FL display lights. The
mechanism does not work.)
C
D
3
An opening screen is not
displayed on the monitor
(The FL display lights. The
mechanism does not work.)
E
F
60
1
2
Diagnosis Contents
SUPPLY Unit.
Are wires of output connector (POWER PCB ASSY) and CP4003
(DVDM Assy) disconnected or damaged ?
Check that the voltage at IC651-pin 10 (K 1) on the FLKY Assy
becomes about 2.7 V when the POWER key is pressed and 0 V when
it is released.
Check that the voltage at OS651-pin 1 (IR) on the OPERATION1 Assy
is in the range between 0 and 3.3 V while receiving signals from the
remote control unit when any key on it is pressed.
• Check the voltage of E+6.8 V and SW+3.3 V on the POWER PCB
ASSY.
• Check the voltage of P.ON-H is about 2.8 V on the POWER PCB
ASSY.
Check that the following voltage are output :
IC4006-pin 5 : 1.8 V, on the DVD MT PCB Assy.
Is a resonator (X4001 : 27MHz) on the DVDMT Assy oscillating ?
• Are the signals input into IC4005-pin 16 (DWE#), pin 19 (DCS#)
and pin 38 (SDCLK) on the DVDMT Assy ?
(Is a signal fluctuating ?)
→ Communication with SDRAM
Is a signal output from IC4004-pin 28 (PRD#) on the DVD MT Assy?
(Is a signal fluctuating for several hundred mS after the power is turned
on ?)
Are the signals of IC4003-pin 5(SDA) and pin 6(SCL) on the DVDMT
Assy fluctuating for one or two seconds after the power is turned ?
Check the video signal path between DVD IC (DVD MT Assy IC4001)
and video-out terminal (see the block diagram)
DV-490V-S
2
3
Possible Defective Points
POWER PCB ASSY
Connector / cable
OPERATION 2 Assy
Tact SW
(when operation of only the
POWER key on the main unit is
not accepted)
OPERATION Assy
Remote receiver section
(when operation of only the
POWER key on the remote
control unit is not accepted)
POWER PCB Assy
DVD MT PCB Assy
1.8 V Regulator IC (IC4006)
DVD MT PCB Assy
Crystal resonator (X4001)
DVD MT PCB Assy
DVD IC (IC4001)
Flash ROM (IC4004)
SDRAM (IC4005)
DVD MT PCB Assy
Flash ROM (IC4004)
DVD MT PCB Assy
EEPROM (IC4003)
DVD MT PCB Assy
Video circuit after DVD IC
(IC4001)
3
4
4