LG HDR688X, Service Manual

Page: 62 / 175

CONTENTS
SECTION 4
RS-01A LOADER PART
ELECTRICAL TROUBLESHOOTING GUIDE
......................................................................................................4-2
THE DIFFERENCE OF DVD-R/RW, DVD+R/RW DISCS AND DVD-ROM
..............................................4-15
1. RECORDING LAYER .................................................................................................................................................4-15
2. DISC SPECIFICATION...............................................................................................................................................4-16
3. DISC MATERIALS ......................................................................................................................................................4-16
4. ORGANIZATION OF THE INNER DRIVE AREA, OUTER DRIVE AREA, LEAD-IN ZONE AND
LEAD-OUT ZONE.......................................................................................................................................................4-20
HOW TO USE TEST TOOL
.......................................................................................................................................4-24
1. ALPC MEASUREMENT SYSTEM..............................................................................................................................4-24
2. ALPC PROGRAM ......................................................................................................................................................4-24
3. EXECUTE ALPC PROGRAM.....................................................................................................................................4-25
4. OPTICAL POWER SETTING .....................................................................................................................................4-27
5. CONFIRM OPTICAL POWER SETTING PARAMETER ............................................................................................4-28
6. OPTICAL POWER SETTING PARAMETER RANGE ................................................................................................4-29
7. ATTACHMENT. OPTICAL POWER MEASUREMENT ...............................................................................................4-30
INTERNAL STRUCTURE OF THE PICK-UP
......................................................................................................4-31
1. BLOCK DIAGRAM OF THE PICK-UP(LPC-812R) ...................................................................................................4-31
2. PICK UP PIN ASSIGNMENT .....................................................................................................................................4-32
3. SIGNAL DETECTION OF THE P/U ...........................................................................................................................4-33
DESCRIPTION OF CIRCUIT
.....................................................................................................................................4-34
1. ALPC (AUTOMATIC LASER POWER CONTROL) CIRCUIT ....................................................................................4-34
2. FOCUS/TRACKING/SLED SERVO CIRCUIT ............................................................................................................4-35
3. SPINDLE SERVO CIRCUIT .......................................................................................................................................4-37
MAJOR IC INTERNAL BLOCK DIAGRAM
.........................................................................................................4-38
LIC121 (AN22113A) : FEP(RF) ANALOG SIGNAL PROCESSOR ................................................................................4-38
IC301 (BD7956FS) : CD-ROM/DVD-ROM 7CH POWER DRIVER ...............................................................................4-41
CIRCUIT DIAGRAMS
..................................................................................................................................................4-42
1. DSP CIRCUIT DIAGRAM ...........................................................................................................................................4-42
2. RF CIRCUIT DIAGRAM .............................................................................................................................................4-44
3. DRIVE CIRCUIT DIAGRAM .......................................................................................................................................4-46
CIRCUIT VOLTAGE CHART
.....................................................................................................................................4-48
PRINTED CIRCUIT DIAGRAMS
..............................................................................................................................4-50
1. MAIN P.C.BOARD(TOP VIEW) .................................................................................................................................4-50
2. MAIN P.C.BOARD(BOTTOM VIEW) .........................................................................................................................4-52