Sony HCD-VZ50MD Service Manual page 41

6-5. USING THE CONTINUOUSLY RECORDED DISC
* This disc is used in focus bias adjustment and error rate check.
The following describes how to create a continuous recording
disc.
1. Insert a disc (blank disc) commercially available.
2. Move the multi-stick and display "CREC 1MODE"(C35).
3. Press the PUSH ENTER button again to display "CREC 1MID".
Display "CREC (0300)" and start to recording.
4. Complete recording within 5 minutes.
5. Press the CLEAR button while REC IT is lit and stop recording.
6. Press the MD Z button while REC IT is off and remove the
disc.
The above has been how to create a continuous recorded data for
the focus bias adjustment and error rate check.
Note :
• Be careful not to apply vibration during continuous recording.
6-6. CHECKS PRIOR TO REPAIRS
These checks are performed before replacing parts according to
"approximate specifications" to determine the faulty locations. For
details, refer to "Checks Prior to Parts Replacement and Adjust-
ments" (See page 11).
6-6-1. Temperature Compensation Offset Check
When performing adjustments, set the internal temperature and room
temperature to 22 to 28ºC.
Checks cannot be performed properly if performed after some time
from power ON due to the rise in the temperature of the IC and
diode, etc. So, perform the checks again after waiting some time.
Checking Procedure:
1. Move the multi-stick to display "TEMP CHECK"(C12).
2. Press the PUSH ENTER button.
3. "T=@@(##) [OK]" should be displayed. If "T=@@ (##) [NG]"
is displayed, it means that the results are bad.
(@@ indicates the current value set, and ## indicates the value
written in the non-volatile memory.)
6-6-2. Laser Power Check
Before checking, check the Iop value of the optical pick-up.
(Refer to 6-8. Recording and Displaying the Iop Information.)
Connection :
Optical pick-up
objective lens
BD (MD) board
CN105 pin 1 (I+3V)
CN105 pin 2 (IOP)
Laser power
meter
Digital volt meter
Checking Procedure:
1. Set the laser power meter on the objective lens of the optical
pick-up. (If cannot set properly, press the m or M button
while REC IT is off and move the optical pick-up.)
Connect the digital volt meter to CN105 pin 1 (I+3V) and
CN105 pin 2 (IOP).
2. Then, move the multi-stick and display "LDPWR CHECK"
(C13).
3. Press the PUSH ENTER button once and display "LD 0.9 mW
$ ". Check that the reading of the laser power meter become
0.82 to 0.91 mW.
4. Press the PUSH ENTER button once more and display " LD
7.0 mW $ ". Check that the reading the laser power meter and
digital volt meter satisfy the specified value.
Specified Value :
Laser power meter reading : 7.0 ± 0.1 mW
Digital voltmeter reading : Optical pick-up displayed value ± 10%
(For details of the method for checking
KMS 260B
this value, refer to "6-8. Recording and
20101
Displaying the Iop Information".)
H0576
R
Iop = 57.6 mA in this case
Iop (mA) = Digital voltmeter reading (mV)/1 ( Ω )
(Optical pick-up label)
5. Press the CLEAR button while REC IT is lit and display
"LDPWR CHECK"(C13) and stop the laser emission.
(The CLEAR button while REC IT is lit, it is effective at all
times to stop the laser emission.)
Note 1: After step 4, each time the PUSH ENTER button is
pressed, the display will be switched between "LD 0.7 mW
$ ", "LD 6.2 mW $
needs to be performed here.
6-6-3. Iop Compare
The current Iop value at laser power 7 mw output and reference Iop
value (set at shipment) written in the nonvolatile memory are
compared, and the rate of increase/decrease will be displayed in
percentage.
Note: Perform this function with the optical pick-up set at room
temperature.
Procedure
1. Move the multi-stick to display "Iop Compare"(C27).
2. Press the PUSH ENTER button and start measurements.
3. When measurements complete, the display changes to
"±xx%yy".
xx is the percentage of increase/decrease, and OK or NG is
displayed at yy to indicate whether the percentage of increase/
decrease is within the allowable range.
4. Press the CLEAR button to end while REC IT is lit.
", and "LD Wp $ ". Nothing
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