Philips CDR880 - Page 13

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SAFETY GUIDELINES FOR THE PROFESSIONAL SERVICE TECHNICIAN
Important
Proper service and repair is important to the safe, reliable operation
of all Philips equipment. The service procedures recommended by
Philips and described in this service manual are effective methods of
performing service operations. Some of these service operations
require the use of tools specially designed for the purpose. The
special tools should be used when and as recommended.
Itis important to note that this manual contains various CAUTIONS
and NOTICES which should be carefully read in order to minimize the
risk of personal injury to service personnel. The possibility exists
that improper service methods may damage the equipment. it also
Is important to understand that these CAUTIONS and NOTICES
ARE NOT EXHAUSTIVE. Philips could not possibly know, evaluate
and advise the service trade of all conceivable ways in which service
might be done or of the possible hazardous consequences of each
way. Consequently, Philips has not undertaken any such broad
evaluation. Accordingly, a servicer who uses a service procedure or
tool which is not recommended by Philips must first satisfy himself
thoroughly that neither his safety nor the safe operation of the
equipment will be jeopardized by the service method selected.
Safety Checks
After the original service problem has been corrected, a complete
safety check should be made. Be sure to check over the entire set,
not just the areas where you have worked. Some previous servicer
may have left an unsafe condition, which could be unknowingly
passed on to your customer. Be sure to check ail of the following:
Fire and Shock Hazard
1. Besure all components are positioned in such a way as to avoid
the possibility of adjacent component shorts. This is especially
important on those units which are transported to and from the
service shop.
2. Never release a repaired unit unless all protective devices such
as insulators, barriers, covers, strain reliefs, and other
hardware have been installed according to the original design.
3. Soldering and wiring must be inspected to locate possible cold
solder joints, solder splashes, sharp solder points, frayed
leads, pinched leads, or damaged insulation (including the ac
cord). Be certain to remove loose solder bails and ail other
loose foreign particles.
4. Check across-the-line components and other components for
physical evidence of damage or deterioration and replace if
necessary. Follow original layout, jead length, and dress.
5. Nolead or component should touch a resistor rated at 1 watt or
more. Lead tension around protruding metal surfaces or edges
must be avoided.
6. Critical components having special safety characteristics are
identified with a A by the Ref. No. in the parts list and enclosed
within a broken line* (where several critical components are
grouped in one area) along with the safety symbol
& on the schematic diagrams and/or exploded views.
Replacement parts without the same safety characteristics
may create shock, fire, or other hazards.
7. When servicing any unit, always use a separate Isolation
transformer for the chassis. Failure to use a separate isolation
transformer may expose you to possible shock hazard, and
may cause damage to servicing instruments.
8. Many electronic products use a polarized ac line cord (one wide
pin ‘on the plug). Defeating this safety feature may create a
potential hazard to the servicer and the user. Extension cords
ibaa do not incorporate the polarizing feature should never be
used.
LASER NOTE:
Fire and Shock Hazard (Continued)
9. After reassembly of the unit, always perform an ac leakage
test or resistance test from the line cord to all exposed metal
parts of the cabinet. Also, check all metal control shafts (with
knobs removed), antenna terminals, handies, screws, etc. to
Be sure the unit is safe to operate without danger of electrical
shock.
* :
Broken line: 5 GEER: 6 SE © ee Ss ee
Leakage Current Cold Check
1. Unplug the ac line cord and connect a jumper between the two
prongs of the plug.
2. Turn on the power switch.
3. Measure the resistance value between the jumpered ac plug
and all exposed cabinet parts of the receiver, such as screw
heads, antennas, and control shafts. When the exposed
metallic part has a return path to the chassis, the reading
should be between 1 megohm and 5.2 megohms. When the
exposed metal does not have a return path to the chassis, the
reading must be infinity. Remove the jumper from the ac line
cord.
WATER
TO PIPE
INSTRUMENTS Baik
EXPOSED (
METAL
PARTS
GROUND)
15000, 10W
Leakage Current Hot Check
1. Do not use an isolation transformer for this test. Plug the
completely reassembled unit directly into the ac outlet.
2. Connect a1.5k, 10W resistor paralleled by a 0.15uF. capacitor
between each exposed metallic cabinet part and a good earth
ground such as a water pipe, as shown above.
3. Use an ac voltmeter with at least 5000 ohms/volt sensitivity to
measure the potential across the resistor.
4. The potential at any point should not exceed 0.75 volts. A
leakage current tester may be used to make this test; leakage
current must not exceed 0.5 milliamps. If a measurement is
outside of the specified limits, there is a possibility of shock
hazard. The receiver should be repaired and rechecked before
returning it to the customer.
5. Repeat the above procedure with the ac plug reversed. (Note:
An ac adapter is necessary when a polarized plug is used. Do
not defeat the polarizing feature of the plug.)
Parts Replacement
1. Many electrical and mechanical parts in Philips equipment have
special safety related characteristics. These characteristics
are often not evident from visual inspection nor can the
protection afforded by them necessarily be obtained by using
replacement components rated for higher voltage, wattage,
etc. The use of a substitute part which does not have the sarne
safety characteristics as the Philips recommended
replacement part shown in this service manual may create
shock, fire, or other hazards. Under no circumstances should
the original design be modified or altered without written
permission from Philips. Philips assumes no liability, express or
implied, arising out of any unauthorized modification of design.
Servicer assumes all liability.
2. Ail lCs and many other semiconductor parts are susceptible to
electrostatic discharges (ESD). Careless handling during
repair can redudé the life of the part drastically.
DANGER ~- Invisible laser radiation when open. AVOID DIRECT EXPOSURE TO BEAM.
CAUTION - Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous
radiation exposure.
CAUTION - The use of optical instruments with this product will increase eye hazard.
VIDE-V10221 / Druck
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PCS 83 972