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NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
break-down because of the potential 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.
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 checking the laser diode emission,
observe from more than 30 cm away from the objective lens.
Notes on chip component replacement
¥ Never reuse a disconnected chip component.
¥ Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
Flexible Circuit Board Repairing
¥ Keep the temperature of the soldering iron around 270 ûC dur-
ing repairing.
¥ Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
¥ Be careful not to apply force on the conductor when soldering
or unsoldering
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE WITH
MARK ! ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY.
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CAUTION
Use of controls or adjustments or performance of
procedures other than those specified herein may
result in hazardous radiation exposure.
This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on
the rear exterior.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
The following caution label is located inside the unit.
MODEL IDENTIFICATION
Ð BACK PANEL ÐSAFETY CHECK-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, ÒmetallizedÓ 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 microampers.).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturersÕ instructions to use these
instruments.
2. 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 voltmeter. The ÒlimitÓ indication is 0.75
V, 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 2 V AC range are suitable. (See Fig. A)
Earth GroundAC
voltmeter
(0.75V) 1.5k
½ 0.15 µF
Fig. A. Using an AC voltmeter to check AC leakage.
To Exposed Metal
Parts on Set
COMPACT DISC DECK RECEIVER SERIAL MODEL NO.
HCD-MD555
MADE IN
NO.
JAPAN
AC: 230V ~ 50/60Hz 90W: AEP, UK model
AC: 110 Ð 120/220 Ð 240V ~ 50/60Hz 90W
: Singapore, Malaysia, Hong Kong, Tourist model
AC: 120V 60Hz 90W: US model
