Roadstar DT-956LCD User manual

Service Manual - DT-956LCD
R
DT-956LCD
Service Manual - DT-956LCD

2
CONTENTS
Page
Disassembly Instructions ..................................................................................................................................... 3
Disassembly Diagram.......................................................................................................................................... 5
Block Diagram ..................................................................................................................................................... 7
Alignment Locations ............................................................................................................................................ 9
Alignment Procedures ....................................................................................................................................... 10
Printed Circuit Board.......................................................................................................................................... 12
Exploded View (Display).................................................................................................................................... 31
Exploded View Part List (Display)...................................................................................................................... 32
Exploded View (Unit) ......................................................................................................................................... 34
Exploded View Parts List (Unit) ......................................................................................................................... 35
Exploded View (Radio Box) ............................................................................................................................... 36
Exploded View Part List (Radio Box)................................................................................................................. 37
Schematic Diagram ........................................................................................................................................... 38
Electrical Parts List ............................................................................................................................................ 51
Specifications..................................................................................................................................................... 63

3
DISASSEMBLY INSTRUCTIONS (UNIT)
1. Using the unlock key that came with the unit or a similar tool, unlock the Mounting Box and remove toward the
rear of the unit.
2. Take out the Cabinet Bottom.
3. Remove six screws (A) from on the power board then remove the Power Board; The Left Support; The Right
Support and the Main Board.
4. Take out the Ring and remove two screws (B) from each side of the base then remove the Base.
5. Remove two screws (C) from on the front support and remove two screws (D) from the rear support.
6. Remove three screws (E) and remove the Front Support.
Remove two screws (F) and remove the Deck and the Rear Support.
7. Remove eight screws (G) from each side of the cabinet top then remove the Rock; The Display and the
Cabinet Top.

4
DISASSEMBLY INSTRUCTIONS (RADIO BOX)
1. Remove six screws (A) from each side of the box top the remove the Antenna Socket and the 22PIN Socket.
2. Remove the screws (B) from on the Heat Sink for Box then remove the RDS Box Top.
3. Remove two screws (C) from on the Heat Sink for Box then remove the IC Bracket and the Heat Sink For
Box.
4. Remove four screws (D) from on the main board then remove the Main Board and the Box Bottom.

5
DISASSEMBLY DIAGRAM (UNIT)

6
DISASSEMBLY DIAGRAM (RADIO BOX)

7
BLOCK DIAGRAM (DVD)

8
BLOCK DIAGRAM (RADIO BOX)

9
ALINGMENT LOCATIONS
LA1787 FM/MWLW TUNER

10
ALIGNMENT PROCEDURES
FM ADJUSTMENT
Equipment Required
zAM IF/RF signal generator
zSolid-state voltmeter (SSVM)
zRegulated DC power supply
z2-CH voltmeter
zDistortion meter
FM Alignment Using FM Signal Generator
Note: Press the radio power switch to on the radio. Signal generator output must be kept as low as possible
to avoid overload and clipping.
Step Generator
Coupling
Generator Display
Setting
Adjustment Remarks
Stereo
Separation
Signal
Generator
to antenna
receptacle
98.1 MHz
Int. 1 kHz
Dev. 75 kHz
L+R = 90 %
pilot = 10 %
98.1 MHz VR1
Adjust AF
output power
at maximum
separating
more than 30 dB
FM SNC
Adjustment
98.1 MHz
Dev. 75 kHz
L+R=90 %
Int. 1 kHz
60dBµV output
98.1 MHz
@ 40 dBµ
98.1 MHz VR3 Stereo Separation
25 dB (±5 dB)
STOP
SENS.
Signal Generator
to antenna
receptacle
98.1 MHz
Mod. 1kHz
Dev 75kHz
98.1 MHz VR4
Adjust AF to stop
station.
Note: The tuner module is well-adjust and adjustment is not recommended.

11
AM ADJUSTMENT
Equipment Required
zMW IF/RF signal generator
zSolid-state voltmeter (SSVM)
zRegulated DC power supply
z2-CH voltmeter
zDistortion meter
MW Alignment Using AM Signal Generator
Note: Press the radio power switch to on the radio. Signal generator output must be kept as low as possible
to avoid overload and clipping.
Step Generator
Coupling
Generator Display
Setting
Adjustment Remarks
MW
Seek
SENS.
Signal Generator
to antenna
receptacle.
1000 kHz
Input level
25 dBµV
1000 kHz VR2 Adjust AF
Stop station.
Note: The tuner module is well-adjust and adjustment is not recommended.

12
PRINTED CIRCUIT BOARDS
MAIN BOARD
TOP VIEW

13
MAIN BOARD
BOTTOM VIEW

14
KEY BOARD
TOP VIEW

15
KEY BOARD
BOTTOM VIEW

16
MONITOR KEY BOARD
TOP VIEW

17
MONITOR KEY BOARD
BOTTOM VIEW

18
CD SERVO BOARD
TOP VIEW

19
CD SERVO BOARD
BOTTOM VIEW

20
POWER BOARD
TOP VIEW