Sony cdp h 300 service manual

Page 2

CDP-H300

SAFETY CH ECK-OUT

After correcting the original service problem,
perform the following safety check before releasing
the set to the customer:

Check the antenna terminals, metal trim, metallized
knobs, screws, and all other exposed metal parts for
AC leakage. Check leakage as described below.

LEAKAGE TEST

The AC leakage from any exposed metal part to
earth ground and from all exposed metal parts to any
exposed metal part having a return to chassis. must
not exceed 0.5 mA (500 microampersl. Leakage
current can be measured by any one of three
methods.

1. A commercial leakage tester, such as the
Simpson 229 or RCA WT-S40A. Follow the
manufacturers' instructions to use these instru-

ments.

u

A battery-operated AC milliammeter. The Data
Precision 245 digital multimeter is suitable for
this job.

3 Measuring the voltage drop across a resistor by
means of a VOM or battery-operated AC volt-
meter. The limit" indication is 0.75V. so
analog meters must have an accurate low
voltage scale. The Simpson 250 and Sanwa
SH-63Trd are examples of a passive VOM that
is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are
suitable. (See Fig, A)

To Exposed Metal
Parts on Set

A C
voltmerer
I0. 75 VI

0.75uF EELS)
'_..J

'=:' E 3th Ground

Fig, A. Using an AC voltmeter to cheek AC leakage.

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SERVICING NOTE

NOTES ON HANDLING THE OPTICAL PICK-
UP BLOCK OR BASE UNIT

The laser diode in the optical pick-up block may
suffer electrostatic breakdown because of the poten-
tial difference generated by the charged electrostatic
load, etc. on clothing and the human body.

During repair, pay attention to electrostatic break-
down and also use the procedure in the printed
matter which is included in the repair parts.

The flexible board is easily damaged and should be
handled with care.

CAUTION

Use of controls or adjustments or performance
of procedures other than those specified herein
may result in hazardous radiation exposure.

NOTES ON LASER DIODE EMISSION CHECK

The laser beam on this model is concentrated so as to be
focused on the disc reflective surface by the objective
lens in the optical pick-up block. Therefore, when check-
ing the laser diode emission, observe from more than 30
cm away from the objective lens.