Sony MDS-S50 - Manual (Page 26)

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MDS-S50
5-6-4. Auto Check
This test mode performs CREC and CPLAY automatically for
mainly checking the characteristics of the optical pick-up. To
perform this test mode, the laser power must first be checked.
Perform Auto Check after the laser power check and Iop compare.
Procedure:
1. Turn the
[ AMS ] knob to display “AUTO CHECK”
(C01).
2. Press the [YES] button. If “LDPWR ” is displayed, it
means that the laser power check has not been performed. In
this case, perform the laser power check and Iop Compare, and
then repeat from enter the test mode.
3. If a disc is in the mechanical deck, it will be ejected forcibly.
“DISC IN” will be displayed in this case. Load a test disc (MDW-
74/GA-1) which can be recorded.
4. If a disc is loaded at step 3, the check will start automatically.
5. When “XX CHECK” is displayed, the item corresponding to
XX will be performed.
When “06 CHECK” completes, the disc loaded at step 3 will be
ejected. “DISC IN” will be displayed. Load the check disc
(TDYS-1).
6. When the disc is loaded in the step 5, the check will automatically
be resumed from “07 CHECK”.
7. After completing to test item 12, check OK or NG will be
displayed. If all items are OK, “CHECK ALL OK” will be
displayed. If any item is NG, it will be displayed as “NG: xxxx”.
When “CHECK ALL OK” is displayed, it means that the optical
pick-up is normal. Check the operations of other parts (spindle
motor, sled motor, etc.).
When displayed as “NG: xxxx”, it means that the optical pick-up
is faulty. In this case, replace the optical pick-up.
5-6-5. Other Checks
All the following checks are performed by the Auto Check mode.
They therefore need not be performed in normal operation.
5-6-6. Traverse Check
5-6-7. Focus Bias Check
5-6-8. C PLAY Check
5-6-9. Self-Recording/Playback Check
5-6-6. Traverse Check
Connection:
Procedure:
1. Connect an oscilloscope to CN105 pin 4 (TE) and CN105
pin 6 (VC) on the BD board.
2. Load a disc (any available on the market). (Refer to Note 1)
3. Press the
M button to move the optical pick-up outside the
pit.
4. Turn the [ AMS ] knob to display “EF MO CHECK”
(C14).
5. Press the [YES] button to display “EFB = MO-R”.
(Laser power READ power/Focus servo ON/tracking servo
OFF/spindle (S) servo ON)
6. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not turn the [ AMS ]
knob.
(Read power traverse checking)
Traverse Waveform
7. Press the [YES] button to display “EFB = MO-W”.
8. Observe the waveform of the oscilloscope, and check that the
specified value is satisfied. Do not turn the [ AMS ]
knob.
(Write power traverse checking)
Traverse Waveform
Note 1: Data will be erased during MO reading if a recorded disc is
used in this adjustment.
Note 2: If the traverse waveform is not clear, connect the oscilloscope
as shown in the following figure so that it can be seen more
clearly.
+
–
oscilloscope
(DC range)
10 pF
330 k
Ω
CN105 pin 4 (TE)
CN105 pin 6 (VC)
BD board
A
B
VC
Specified value : Below 10% offset value
Offset value (%) = X 100
I A – B I
2 (A + B)
A
B
VC
Specified value : Below 10% offset value
Offset value (%) = X 100
I A – B I
2 (A + B)
+
–
oscilloscope
(DC range)
V: 0.1 V/div
H: 10 ms/div
BD board
CN105 pin 4 (TE)
CN105 pin 6 (VC)
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