Denon DCD-425 Service Manual - Page 11

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Cautions

for

Handling

the

Laser

Pick-up

The

laser

pick-up

KSS-210A

is

assembled

and

precisely

adjusted

using

a

sophisticated

manufacturing

process

in

our

plant.

Do

not

disassemble

or

attempt

to

readjust

it.

Please

keep

the

following

instructions

carefully

in

handling

pick-up.

1.

Handle

with

Care

(1)

Storage

Do

not

store

the

pick-up

in

dusty,

high

-temperature

or

high

-humidity

environments.

(2)

Please

take

care

for

preventing

from

shock

by

falling

down

or

careless

handling.

2.

Laser

Diode

(LD)

(1)

Protect

your

eyes

The

laser

beam

may

damage

the

human

eye,

since

the

intensity

of

the

focused

spot

may

reach

7x10

3

W/cm

2

even

if

the

intensity

at

the

objective

lens

is

400μW

maximm.

As

the

light

beam

spreads

after

focused

through

the

objective

lens,

it

does

not

effect

you

in

the

place

as

far

as

more

than

30

cms.

However,

do

not

look

at

the

laser

light

beam

either

through

the

objective

lens

directly

nor

another

lens

or

a

mirror.

(2)

Poison

of

As

Since

the

LD

chip

contains

As

(Arsenic),

as

GaAs

+

GaAlAs,

as

known

as

the

poison,

although

the

poison

is

relatively

weak,

in

comparing

with

others,

e.g.

As2O3,

AsCI3

etc.,

and

the

amount

is

small,

avoid

putting

the

chip

in

acid

or

an

alkali

solution,

heating

it

over

200

°C

or

putting

it

into

your

mouth.

(3)

Avoid

surge

current

or

electrostatic

discharge

The

LD

may

be

damaged

or

deteriorated

by

its

own

strong

light

if

a

large

current

is

supplied

to

it,

even

if

only

a

short

pulse.

Make

sure

that

there

is

no

surge

current

in

the

LD

driving

circuit

by

switches

or

else.

Be

careful

to

handle

pick-up

as

it

may

be

damaged

in

a

moment

by

human

electrostatic

discharge.

The

pins

of

the

LD

are

short-

circuited

by

solder

for

protection

during

shipment.

For

safety

handling

of

an

LD,

grounding

the

human

body,

measuring

equipments

and

jig

is

strongly

recommended.

And

still

it is

further

desirable

to

make

use

of

mat

on

the

platform

and

floor

for

handling

the

LD.

To

open

the

short

circuit,

remove

the

soldering

quickly

with

a

soldering

iron

whose

matal

part

is

grounded.

The

temperature

of

the

soldering

iron

should

be

less

than

320

°C

(30W).

3.

Actuator

(1)

The

performance

of

the

actuator

may

be

effected

if

magnetic

material

is

located

nearby,

since

the

actuator

has

a

strong

magnetic

circuit.

Do

not

permit

dust

to

enter

through

the

clearance

of

the

cover.

(2)

Cleaning

the

lens

It

may

change

the

specifications

by

attaching

dust

or

ash

on

the

object

lens.

Clean

the

lens

with

a

cleaning

paper

dampened

with

a

little

water,

not

pressing

lens

with

so

much

strength

by

the

cleaning

paper.

4.

Metal

Bearing

As

the

metal

bearing

of

Cu

-compound

sintered

alloy

is

impregnated

with

FROIL946P

(by

the

Kanto

Kasei

Kogyo),

never

fail

to

supply

the

bushing

with

the

same

lubricant

at

the

time

of

replacing

the

pick-up.

5.

Handling

Please

handle

the

laser

pick-up

with

holding

the

slide

base.

(rosin

molded

part).

When

either

a

part

of

human

body

or

some

other

things

may

happen

to

touch

directly

with

the

circuit

part

of P.W.Board,

it

may

cause

deterioration,

take

careful

attention

in

handling

this

base.

6.

Deterioration

When

difficulty

occurs

either

in

focus

or

tracking

adjustment

nor

able

to

adjust

the

focus

or

tracking,

it

seems

that

the

laser

pick-up

is

deteriorated.

In

these

cases,

check

a

value

of

laser

diode

current

and

give

a

decision

for

deterioration.

7.

Fundamental

Deterioration

Decision

of

Laser

Pick-up

(1)

If

a

voltage

value

in

between

+5V

and

Q101(Emitter)

of

the

Main

Unit,

the

value

of

laser

diode

current

"iop"

can

be

found

by

a

formula

V1

"iop

1"

7-722

(2)

If

an

"iop"

exceeds

±10%

compared

with

the

'OP

indication

on

the

laser

pick-up

nameplate,

there

is

a

fair

chance

for

deterioration

when

it

is

checked

under

a

circumambient

temperature

23

°C.

(3)

When

the

circumambient

temperature

changes

±10

°C,

"iop

1"

will

change

±5%.

The

"iop

1"

will

also

be

changed

by

the

passage

of

time.

(4)

In

case

of

the

above

conditions

taking

into

consideration

and

performed

the

adjustment

in

proper

way,

if

the

HF

level

at

TP4

(RF)

on

Main

Unit,

and

in

between

GND4

becomes

1V

or

lesser

values;

or

a

jitter

occurs

great,

the

laser

pick-up

may

be

deteriorated.

11

Denon DCD-425 Service Manual - Page 11

Cautions, Handling, Laser, Pick-up

Page 11 highlights