Safety & Maintenance Instructions, Warnings And Notes - Philips M123A Service Manual

Colour Television
2. Safety & Maintenance Instructions, Warnings and Notes
2.1 Safety Instructions For Repairs
Safety regulations require that during a repair:
--Due to the 'hot' parts of this chassis, the set must be connected to the AC power via an
isolation transformer.
-- Safety components, indicated by the symbol _, should be replaced by components identical
to the original ones.
-- When replacing the CRT, safety goggles must be worn. Safety regulations require that after a
repair, the set must be returned in its original condition. Pay particular attention to the
following points:
-- General repair instruction: as a strict precaution, we advise you to re-solder the solder
connections through which the horizontal deflection current is flowing, in particular:
--- all pins of the line output transformer (LOT)
--- fly-back capacitor(s)
--- S-correction capacitor(s)
--- line output transistor
--- pins of the connector with wires to the deflection coil
--- other components through which the deflection current flows.
* Note: This re-soldering is advised to prevent bad connections due to metal fatigue in solder
connections and is therefore only necessary for television sets more than two years
Old.
-- Route the wire trees and EHT cable correctly and secure them with the mounted cable clamps.
-- Check the insulation of the AC power cord for external damage.
-- Check the strain relief of the AC power cord for proper function, to prevent the cord from
touching the CRT, hot components, or heat sinks.
-- Check the electrical DC resistance between the AC plug and the secondary side (only for sets
that have an isolated power supply). Do this as follows:
1. Unplug the AC power cord and connect a wire between the two pins of the AC plug.
2. Turn on the main power switch (keep the AC power cord unplugged!).
3. Measure the resistance value between the pins of the AC plug and the metal shielding of the
tuner or the aerial connection of the set. The reading should be between 4.5 M and 12 M .
4. Switch the TV OFF and remove the wire between the two pins of the AC plug.
Check the cabinet for defects, to prevent the possibility of the customer touching any
Internal parts.
2.2 Maintenance Instructions
It is recommended to have a maintenance inspection carried out by qualified service
personnel. The interval depends on the usage conditions:
--- When the set is used under normal circumstances, for example in a living room, the
recommended interval is hree to five years.
--- When the set is used in an environment with higher dust,grease or moisture levels, for
example in a kitchen, the recommended interval is one year.
--- The maintenance inspection includes the following actions
1. Perform the 'general repair instruction' noted above.
2. Clean the power supply and deflection circuitry on the chassis.
3. Clean the picture tube panel and the neck of the picture tube.
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Chassis: M123A