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7
SAFETY CHECK-OUT
(US model only)
After correcting the original service problem, perform the
following safety checks 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
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 manufacturers’ 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 “limit” 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 2V AC range are suitable. (See
Fig. A)
Fig. A. Using an AC voltmeter to check AC leakage.
0.15
µ
F
To Exposed Metal
Parts on Set
1.5k
Ω
AC
voltmeter
(0.75V)
Earth Ground
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK
0
OR DOTTED LINE WITH
MARK
0
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.
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.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous radiation
exposure.
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be
damaged by heat.
Flexible Circuit Board Repairing
• Keep the temperature of soldering iron around 270˚C
during 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.
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.
FOR CD
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.
FOR MD
NOTES ON LASER DIODE EMISSION CHECK
Never look into the laser diode emission from right above when
checking it for adjustment. It is feared that you will lose your sight.
This caution
label is located
inside the unit.
SECTION 1
SERVICE NOTES
Summary of Contents for HCD-ZX50MD
Page 9: ...9 BD CD BOARD To repair the BD CD board remove the bottom plate Bottom view ...
Page 66: ...HCD ZX50MD 66 66 7 11 SCHEMATIC DIAGRAM MAIN 1 4 SECTION See page 65 for Printed WIring Board ...
Page 67: ...HCD ZX50MD 67 67 7 12 SCHEMATIC DIAGRAM MAIN 2 4 SECTION See page 65 for Printed WIring Board ...
Page 75: ...HCD ZX50MD 75 75 7 20 SCHEMATIC DIAGRAM AMP US AEP UK G AED CIS model SECTION ...
Page 77: ...HCD ZX50MD 77 77 7 22 SCHEMATIC DIAGRAM AMP E MX AR HK MY SP KR AUS model SECTION ...
Page 81: ...HCD ZX50MD 81 81 7 26 SCHEMATIC DIAGRAM SWITCH SECTION ...
Page 83: ...HCD ZX50MD 83 83 7 28 SCHEMATIC DIAGRAM CD MECHANISM SECTION 09 Page 68 Page 68 R S ...
Page 116: ...116 MEMO ...