Philips 7629, Service Manual

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TV SAFETY NOTES
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 all of the
following:
Fire and Shock Hazard
Implosion
X-Radiation
Leakage Current Cold Check
Leakage Current Hot Check
Picture Tube Replacement
Parts Replacement
WARNING: Before removing the CRT anode cap, turn the unit OFF and short the HIGH VOLTAGE to
the CRT DAG ground.
SERVICE NOTE: The CRT DAG is not at chassis ground.
IMPLOSION
1. All picture tubes used in current model receivers are equipped with an integral implosion system.
Care should always be used, and safety glasses worn, whenever handling any picture tube. Avoid
scratching or otherwise damaging the picture tube during installation.
2. Use only replacement tubes specified by the manufacturer.
X-RADIATION
1. Be sure procedures and instructions to all your service personnel cover the subject of X-radiation.
Potential sources of X-rays in TV receivers are the picture tube and the high voltage circuits. The
basic precaution which must be exercised is to keep the high voltage at the factory recommended
level.
2. To avoid possible exposure to X-radiation and electrical shock, only the manufacturer's specified
anode connectors must be used.
3. It is essential that the service technician has an accurate HV meter available at all times. The
calibration of this meter should be checked periodically against a reference standard.
4. When the HV circuitry is operating properly there is no possibility of an X-radiation problem. High
voltage should always be kept at the manufacturer's rated value - no higher - for optimum
performance. Every time a color set is serviced, the brightness should be run up and down while
monitoring the HV with a meter to be certain that the HV is regulated correctly and does not exceed
the specified value. We suggest that you and your technicians review test procedures so that HV and
HV regulation are always checked as a standard servicing procedure, and the reason for this prudent
routine is clearly understood by everyone. It is important to use an accurate and reliable HV meter. It
is recommended that the HV reading be recorded on each customer's invoice, which will
demonstrate a proper concern for the customer's safety.