Panasonic CT30WX54J - 30" COLOR TV, Руководство по обслуживанию

Страница: 3 / 296

1. Safety precautions
General guidelines
An isolation transformer should always be used during the servicing of a receiver whose
chassis is not isolated from AC power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injuryfrom electrical shocks. It will
also protect the receiver from being damaged by accidental shorting that may occur during
servicing.
When servicing, observe the original lead dress, especially in the high voltage circuit. Replace
all damaged parts (also parts that show signs of overheating.)
Always replace protective devices, such as fish paper, isolation resistors and capacitors, and
shields after servicing the receiver. Use only manufacturer’s recommended rating for fuses,
circuits breakers, etc.
High potentials are present when this receiver is operating. Operation of the receiver without
the rear cover introduces danger for electrical shock. Servicing should not be performed by
anyone who is not thoroughly familiar with the necessary precautionswhen servicing high
voltage equipment.
Extreme care should be practiced when handling the picture tube. Rough handling may cause it
to implode due to atmospheric pressure. (14.7 lbs per sq. in.). Do not nick or scratch the glass
or subject it to any undue pressure. When handling, usesafety goggles and heavy gloves for
protection. Discharge the picture tube by shorting the anode to chassis ground (not to the
cabinet or to other mounting hardware). When discharging connect cold ground (i.e. dag
ground lead) to the anode with a wellinsulated wire or use a grounding probe.Avoid prolonged
exposure at close range to unshielded areas of the picture tube to prevent exposure to x ray
radiation.
The test picture tube used for servicing the chassis at the bench should incorporate safety
glass and magnetic shielding. The safety glass provide shielding for the tube viewing area
against x ray radiation as well as implosion. The magnetic shieldlimits the x ray radiation
3