Roadstar LCD7080DVBT User manual

1 Specification.....................................................…................................... 2
2 Block Diagram.................................….....................................................4
3 General AlignmentInstruction..............................................................5
4 Troubleshooting..................................................................................... 7
5 Printed Circuit Board............................................................................12
6 Explode View.........................................................................................13
7 IC Block Diagram and Lead Identification.........................................29
8 Schematic Diagram..............................................................................39
CONTENTS
. 1 .

Description Condition Unit Limit Nominal Result
Video Signal Level
75% collr bar,75ohm
Vp-p 0.7 0.1 1.0
SYNC Lever Vp-p 0.3 0.1 0.3
Video out lever Vp-p 1.0 0.2 1.0
Video out lever Vp-p 1.0 0.2 1.0
Audio
out lever 1KHz/0dB V1.4 0.2 1.25-1.4
Signal-to-noise ratio Infinity
Zero/-&dB/l&R 0dB 80 80
Dynamic range 1KHz/60dB 0dB 85 85
Power Consumption
DC 9V
Standby W00
Rating W10 10
SPECIFICATION
HEADPHONE mW03 2 3
1KHz,400mV
OUTPUT
HEADPHONE <1mV
NOISE No signal mV <1mV
500 500
Spk max output L
R
1KHz/0dB
1KHz/0dB
mW0
mW0
100
500 500100
Headphone S/N
Spk S/N
Infinity
Zero/-&dB/l&R 0dB 75 75
Infinity
Zero/-&dB/l&R 0dB 50 50
. 2 .

Vx1827 7 INCH
LCD
PANEL
A 8430
T
DC
DC M 1206
P
HIGH
VOLTAGE
OSC
4
27
6
H.V
TRAN
BLOCK DIAGRAM
LCD
MAIN PART
656-D0
656-D7
.
.
.
.
.
.
656-D0
656-D7
.
.
.
.
.
.
CCIR0
CCIR7
.
.
.
.
.
.
. 3 .

GENERAL ALIGNMENT INSTRUCTION
The Main PCB of Monitor Modification:
1. Input voltage is 6.8V-16V, input signal is test circuit BY 5418.
2. Adjust VR1 to get good performance.
. 4 .

TROUBLESHOOTING
LCD
REMEDY
SYMPTOM CAUSE
& Replace C256(10P/3000V)
2) NO Picture & Defective C256
& Defective IC At8430 Cw3406.
3) No Picture, Picture no
Good & Replace IC At8430 Cw3406
& Replace IC 4558
4) Luminesce no good & Defective IC (U3 4558).
& Replace Y1(20MHz).
5) Color is no good & Defective Y1(20MHz).
& Replace IC U2(VX1827).
6) SYNC no good & Defective IC U2(VX1827).
& Replace IC U2(VX1827).
7) TINT no good & Defective IC U2(VX1827)
& Replace IC U1(1026).
8) NO Picture & Defective IC U1(1026).
& Replace GND-LINE
9) Picture no good & GND LINE-BRAKE
& Replace LCD
10) NO PICTURE & Defective LCD.
MAIN PART
1) No Power & Power source is not correct.
The positive and negative
does not match the unit.
& Power button defective.
& Replace power source.
& Defective triode U4
& Charge the position of
Positive and negative.
& Replace power button.
& Replace U4(LS2822)
2) No Picture
& Defective U9 SDRAM
& Replace U11 (24C02N).
& Replace U9 SDRAM OR
& DefectiveU11 (24C02N).
& Replace IC CT212T.
OR U8 FLASH .
& Defective IC(U10, CT212T)
U8 FLASH .
3) No Sound & Defective U14 (TDA2822)
& Replace U13 (C4558).
& Replace U14 (TDA2822)
& Defective U13 (C4558).
4) Sound no good & Replace U13 (C4558).
& Replace U14 (TDA2822)
& Defective U13(C4558).
& Defective U14 (TDA2822)
& Defective U12 (4334).
& Defective Q4(3095).
& Defective Q12(9926) & Replace Q12(9926).
5) No Power
& Replace U12 (4334)
& Replace Q4(3095)
& Replace IC (U10,CT212T).
6) No key function & Defective IC(U10,CT212T).
7) No remote control
Function
& Defective Ir1
& Key is Defective.
& ReplaceIR1.
& Replace keys.
& Replace U2(VX1827)
1) NO Picture & Defective IC U2(VX1827)
LCD MONITOR PART
. 5 .

PRINTED CIRCUIT BOARD
Monitor HV PCB
Top View Bottom View
. 6 .

PRINTED CIRCUIT BOARD
Main PCB
Top View
. 7 .

PRINTED CIRCUIT BOARD
Main PCB
Top View
. 8 .

EXPLODED VIEW
. 9 .

IC BLOCK DIAGRAM & DESCRIPTION
Vx1827
. 10 .

IC BLOCK DIAGRAM & DESCRIPTION
Vx1827
. 11 .

IC BLOCK DIAGRAM & DESCRIPTION
A8430EEK
. 12 .

IC BLOCK DIAGRAM & DESCRIPTION8D02D
S8232
. 13 .

IC BLOCK DIAGRAM & DESCRIPTION8D02D
24C02
. 14 .

IC BLOCK DIAGRAM & DESCRIPTION8D02D
CS4334
. 15 .

SCHEMA TIC DIAGRAMS
TFT-POWER
. 16 .

SCHEMA TIC DIAGRAMS
VX1827
. 17 .

SCHEMA TIC DIAGRAMS
PANEL
. 18 .

SCHEMA TIC DIAGRAMS
CHANGE
. 19 .