CMT-PX333, HCD-PX333 - Sony Audio Service Manual (repair manual). Page 41

41

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. Press the

.

  “R”

or

>

  “R”

button to display “AUTO

CHECK” (C01).

2. Press the

ENTER/YES “R”

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 MD 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.

All the following checks are performed by the Auto Check mode.
They therefore need not be performed in normal operation.
6-6. Traverse Check
6-7. Focus Bias Check
6-8. C PLAY Check
6-9. Self-Recording/Playback Check

Procedure:
1. Connect an oscilloscope to CN105 pin 4 (TE) and CN105 pin

6

 (VC) on the BD (MD) board.

2. Load a disc (any available on the market). (Refer to Note 1)
3. Press the

M

 “R”

button to move the optical pick-up outside

the pit.

4. Press the

. 

“R”

or

>

  “R”

button to display “EF MO

CHECK”(C14).

5. Press the

ENTER/YES “R”

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 press the

. 

“R”

 or

 >

 “R”

button.

(Read power traverse checking)

Traverse Waveform

7. Press the

ENTER/YES “R”

button to display “EFB = 

 MO-

W”.

8. Observe the waveform of the oscilloscope, and check that the

specified value is satisfied. Do not press the

. 

“R”

 or

 >

 “R”

button.

(Write power traverse checking)

Traverse Waveform

Data will be erased during MO reading if a recorded disc is
used in this adjustment.

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 (MD) 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 (MD) board

CN105 pin 

4

 (TE)

CN105 pin 

6

 (VC)