ZS-M30 - Sony Audio Service Manual (repair manual). Page 21

21

6. CHECK 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 4).

Checking Procedure:
1. Set the laser power meter on the objective lens of the optical

pick-up. (When it cannot be set properly, press the  m  but-ton

or  M  button to move the optical pick-up)
Connect the digital voltmeter to TPO 502 (I+3 V) and TP503 (IOP)
on the MD board.

2. Turm the JOG dial to display “LDPWR CHECK”.
3. Press the  YES/ENTER  button once to display “LD 0.9 mW $

 ”. Check that the reading of the laser power meter become

0.80 to 0.96 mW.

4. Press the  YES/ENTER  button once more to display “LD 7.0

mW $ 

 ”. Check that the reading the laser power meter and

digital voltmeter satisfy the specified value.

Specified Value:
Laser power meter reading : 6.8 - 7.2 mW
Digital voltmeter reading : Value on the optical pick-up label

±

 10 %

5. Press the  NO/CANCEL  button to display “LDPWR CHECK”

and stop the laser emission.
(The  NO/CANCEL  button is effective at all times to stop the
laser emission)

: After step 4, each time the  YES/ENTER  button is pressed,

the display will be switched “LD 0.7 mW $ ”,
“LD 6.2 mW $ 

 ”,

and “LD WP 

 $ ”. Nothing needs to be performed

here.( 

= correction)

6-2. Focus Bias Check
Change the focus bias and check the focus tolerance amount.
Checking Procedure:
1. Load the test disc (MDW-74/AU-1).
2. Turn the JOG dial to display “CPLAY MODE”.
3. Press the  YES/ENTER  button twice to display “CPLAY  MID”.
4. Press the  NO/CANCEL  button when “C1 = 

 AD = 

 ”

is displayed.

5. Turn the JOG dial to display “FBIAS CHECK”.
6. Press the  YES/ENTER  button to display “ 

 / 

 c = 

 ”.

The first four digits indicate the C1 error rate, the two digits
after (( / )) indicate ADER, and the 2 digits after “c =” indicate
the focus bias value.
Check that the C1 error is below 50 and ADER is below 2.

7. Press the  YES/ENTER  button to display “ 

 / 

 b = 

 ”.

Check that the C1 error is about 200 and ADER is below 2.

8. Press the  YES/ENTER  button to display “ 

 / 

 a = 

 ”.

Check that the C1 error is about 200 and ADER is below 2.

9. Press the  NO/CANCEL  button, then press the  Z  (MD)

button and take out the test disc.

MO Error Rate Check
Checking Procedure:
1. Load the test disc (MDW-74/AU-1).
2. Turn the JOG dial to display “CPLAY MODE”.
3. Press the  YES/ENTER  button to display “CPLAY MID”.
4. The display changes to “C1 = 

 AD = 

 ”.

5. If the C1 error rate is below 80, check that ADER is below 2.
6. Press the  NO/CANCEL  button to stop playback, then press

the  Z  (MD) button and take out the test disc.

Checking Procedure:
1. Load the check disc (MD) TDYS-1.
2. Turn the JOG dial  to display “CPLAY MODE”.
3. Press the  YES/ENTER  button twice to display “CPLAY  MID”.
4. The display changes to “C1 = 

 AD = 

 ”.

5. Check that the C1 error rate is below 50.
6. Press the  NO/CANCEL  button to stop playback, then press

the  Z  (MD) button and take out the check disc.

laser
power meter

Optical pick-up
objective lens

 

 

 

 

R622

C508

C521

C512

L503

C502

R511

C518

C511

C505

R505

R510

Q503

R508

R513

R509

R517

C519

C517

C520 C522

R519

R516

R512

C506

R504

R503

Q506

Q507

Q505

Q504

R518

Q502

R515

IC502

R5

2

L501

L506

C611

R633

Q501

R514

R502

C607

 

 

 

 

 

TP503

(IOP)

TP502
(I+3V)

(TE)

1

36

25

24

13

15

20

37

48

45

40

30

35

5

1012

TP502 (I+3V)

TP503 (IOP)

MD BOARD (SIDE B)

digital voltmeter

KMS260B

27X40
B0825

lOP=82.5 mA in this case
lOP (mA) = Digital voltmeter reading (mV)/3.3 (

Ω

)

(Optical pick-up label)