3-6
47
82
IC502
CPLD
DSP-RST
TSTSG
110
IC201
DSP IC
IC202
RF IC
Let’s look over the initial step of DSP
1) First. DSP IC receive the DSP - Reset from
CPLD
2) This reset signal get DSP initialized and DSP is
ready to do first step for servo
3) TSTSG from DSP is the test signal for checking
the PLL- loop
4) RF IC regard this test signal as RF signal which
is coming from P/up and send this signal to
DSP. DSP perform the procedure of PLL-loop
by using this signal.
5) after checking the PLL-loop, the second step is
followed. the second step will be explained on
next page…..
if TSTSG doesn’t appear, check DSP and
replace. if the unit doesn’t work normally, even
though the both signals are OK.Check the RF
IC and replace.
DSP-RST
Vcc(3.3V)
Reset period
720 Khz
4.3 Mhz
TSTSG
M/D
ASSY
LD-DVD
CN201
IC202
RF IC
Let’s look over the initial step of servo
1) when the tray is closed, first of all, it should be
checked whether there is disc or not on tray
2) CD laser is turn on and the lense is moved. if
there is a disc on tray, RF signal will appear
3) next, it should be confirmed which disc is that.
CD or DVD.
4) the following step will be done continuously CD -
Laser on -> move lense -> DVD - laser on ->
move lense. in according to disc type, there will
be RF signal…
5) after confirming disc, CD or DVD laser turn on
and focus servo is executed…
the below picture is related signals when DVD
disc is inserted
move lense
CD laser on
DVD laser on
F+
CD/DVD
LD-CD
LD-DVD
1) ~ 2)
4)
5)
6)
9. Checking the first step of servo (1)
10. Checking the second step of servo (2)
