Reference Voltage 2; Checking The Initial Step Of M/D Ass'y - Zenith XBV443 Service Manual

5. Reference Voltage 2

We can see how the reference voltage,
mentioned previous page, will work on servo
control..
1) The DC level of RF signal from P/up is 2.1V
2) The DC level of T.E and F.E is 1.65V
3) Correct DC level of these signal make servo
work normally.
Reference 2.1V
IC202 F.E
T.E
(STL6316)
TacT Reference 2.8
IC201
(L6560)

6. Checking the initial step of M/D Ass'y

Let's look over the initial action of M/D...
1) When the tray is closed, CLOSE-SW should
be changed from 5V to 0V and DSP need to
detect this change
2) Feeding Motor move the P/up to inner area until
the LIMIT SW is detected
3) After DSP detect the LIMIT SW, CD laser is
turned on and go to the next step
M/D
ASSY
FM+
IC201
PMD02
(L6560)
CLOSE_SW
IC202
(STL6317)
Pick-Up
PMD03
LIMIT_SW
CD_LD
Even though, the reference voltage come out
correctly from DSP,
If A/B/C/D are not biased by 2.1V, and checking
the P/up is needed.
If the DC level of T.E is not 1.65V, check DSP
and replace it...
In case of FE, procedure is same
FE
1.65V
TE
1.65V
2.1V
A/B/C/D
4) if there is a DISC on the tray, the RF will be
detected by the CD laser and go to next step..
Check the CLOSE-SW and LIMIT-SW
if anything of the both is not detected, the next
step won't go on. This means that even though
there is a DISC on the tray the DISC will not
rotate.
Tray close
CLOSE-SW
FM+
LIMIT-SW
Limit sw
detect
CD_LD
3-58
P/up move
to inner area
CD_LD on