Philips MX975D, Service Manual

Page: 9 / 116

6. Observe original lead dress. Take extra care to assure correct lead dress in the following areas: a.
near sharp edges, b. near thermally hot parts - be sure that leads and components do not touch
thermally hot parts, c. the ac supply, d. high voltage, and e. antenna wiring. Always inspect in all areas
for pinched, out of place, or frayed wiring. Check ac power cord for damage.
7. Components, parts, and/or wiring that appear to have overheated or are otherwise damaged should
be replaced with components, parts, or wiring that meet original specifications. Additionally, determine
the cause of overheating and/or damage and, if necessary, take corrective action to remove any
potential safety hazard.
PRECAUTIONS DURING SERVICE
A. Parts identified by the symbol are critical for safety. Replace only with part number specified.
B. In addition to safety, other parts and assemblies are specified for conformance with regulations
applying to spurious radiation. These must also be replaced only with specified replacements.
Examples:
RF converters, RF cables, noise blocking capacitors, and noise blocking filters, etc.
C. Use specified internal wiring. Note especially:
1) Wires covered with PVC tubing
2) Double insulated wires
3) High voltage leads
D. Use specified insulating materials for hazardous
live parts. Note especially:
1) Insulation Tape
2) PVC tubing
3) Spacers
4) Insulators for transistors
E. When replacing ac primary side components (transformers, power cord, etc.), wrap ends of wires
securely about the terminals before soldering.
F. Observe that the wires do not contact heat producing parts (heatsinks, oxide metal film resistors,
fusible resistors, etc.)
G. Check that replaced wires do not contact sharp edged or pointed parts.
H. When a power cord has been replaced, check that 10-15 kg of force in any direction will not
loosen it.
I. Also check areas surrounding repaired locations.
J. Use care that foreign objects (screws, solder droplets, etc.) do not remain inside the set.
K . Crimp type wire connector
When replacing the power transformer in sets where the connections between the power cord and power
transformer primary lead wires are performed using crimp type connectors, in order to prevent shock
hazards, perform carefully and precisely the following steps.