Sony HCD-J300 Service Manual Download

Page: 32 / 94

HCD-J300

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 Adjustments
in MD” (see page 26).

6-1. Temperature Compensation Offset Check

When performing adjustments, set the internal temperature and room
temperature to 22 to 28ºC.

Procedure:
1. Press the

“R”

button to display “TEMP

CHECK” (C12).

2. Press the

ENTER/YES “R”

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.)

6-2. Laser Power Check

Before starting adjustment;
The laser power adjustment value changes depending upon the types
of the optical pick-up (KMS-260B or KMS-260E).
Check the type of the optical pick-up before starting adjustment.
(See the illustrations “The method of ideutifying the optical pick-
up” on page 36)
Before checking, check the Iop value of the optical pick-up.
(Refer to 8. Recording and Displaying the Iop Information (see page
35)

Connection:

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

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

“R”

button

“R”

button to move the optical pick-up.)

Connect the digital volt meter to CN105 pin

(I+3V) and

CN105 pin

(IOP).

2. Then, press the

“R”

button and display

“LDPWR CHECK” (C13).

3. Press the

ENTER/YES “R”

button once and display “LD

0.9mW$

”. Check that the reading of the laser power meter

becomes specified value.

4. Press the

ENTER/YES “R”

button once more and display “ LD

8.4mW$

”. Check that the reading the laser power meter and

digital volt meter satisfy the specified value.

Specified Value:
Laser power meter reading :

Digital voltmeter reading : Optical pick-up displayed value ± 10%

5. Press the

MENU/NO “R”

button and display “LDPWR CHECK”

(C13) and stop the laser emission.
(The

MENU/NO “R”

button is effective at all times to stop the

laser emission.)

Note:

After step 4, each time the

ENTER/YES “R”

button is pressed, the

display will be switched to “LD 0.7W$

”and “LD 7.5mW$

”

“LD WP

”. Nothing needs to be performed here.

Checking Location: BD board (see page 39)

6-3. Iop Compare

The current Iop value at laser power 8.4 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 tempera-
ture.

Procedure:
1. Press the

“R”

button to display “Iop Compare”

(C27).

2. Press the

ENTER/YES “R”

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

MENU/NO “R”

button to end.

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. Press the

“R”

button and display “CREC 1MODE”

(C35).

3. Press the

ENTER/YES “R”