Safety Precautions; Product Safety Notice - Hitachi C21-FL21F Service Manual

SAFETY PRECAUTIONS

WARNING:
The following precautions should be
opserved.
1. Do not install , remove, or handle the picture tube in
any manner unless shatter proof goggles are worn.
People not so equipped should be kept away while
picture tubes are handled. Keep picture tube away
from the body while handing.
2. When service is required, an isolation transformer
should be inserted between power line and the
receiver before any service is performed on the
chassis.
3. When replacing the chassis in the cabinet,ensure
all the protective devices are put back in place,such
as barriers, non - metallic knobs, adjustment or
compartment covers or shields, isolation resistors/
capacitors, etc.
4. When service is required, observe the original lead
dressing. Extra precaution should be taken to
assure correct lead dressing in the high voltage
circuitry area. Particularly note the R. G. B. lead
dressing. Ensure they are dressed well away from
the horizontal scan and F.B.T. circuitry.
5. Always use the manufacturer ' s replacement
component. Always replace original spacers and
maintain lead lengths. Especially critical components
are indicated thus
should not be replaced by other makes.
Furthermore, where a short circuit has occurred,
replace those components that indicate evidence of
overheating.
6. Before returning a serviced receiver to the customer,
the service technician must thoroughly test the unit
to be certain that it is completely safe to operate
without danger of electrical shock, and be sure that
no protective device built into the instrucment by the
manufacturer has became defective, or inadvertenly
damaged during servicing. Therefore, the following
checks are recommended for the continued
protection of the customers and service techninians.
INSULATION
Insulation resistantce should not be less than 7 MΩ at
500 V DC between the mains poles and any accessible
metal parts. Also, no flashover or breakdown should
occur during the dielectric strength test, applying 3kV
AC or 4.25kV DC for two seconds between the main
poles and accessible metal parts.
on the parts list and
HIGH VOLTAGE
High voltage should always be kept at the rated value
of the chassis and no higher. Operating at higher
voltages may cause a failure of the picture tube or high
voltage supply, and also, under certain circumstances
could produce X-radiation moderately in excess of de-
sign levels. The high voltage must not, under any cir-
cumstances, exceed 34kV on the chassis.
X-RADIATION
TUBES : The primary source of X - radiation in this
receiver is the picture tube. The tube utilized for the
above mentioned function in this chassis is specially
constructed to limit X - radiatuion.
For continued X-radiation protection, replace tube with
the same type as the original, HITACHI approved type.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in HITACHI
television receiver have special safety related
characteristics. These characteristics are often not
evident from visual inspection, nor can be protection
afforded by them necessarily be obtained by using
replacement components rated for higher voltage,
wattage, etc. Replacement parts which have these
special safety characteristics are identified by marking
with a on the schematics and replacement
parts list in this Service Manual.The use of a substitute
replacement component which does not have the same
safety characteristics as the HITACHI recommended
replacement one, shown in the parts list in this Service
Manual, may create electrical shock, fire, X - radiation,
or other hazards.
Product Safety is continuously under review and new
instructions are issued from time to time. For the latest
information,always consult the current HITACHI Service
Manual. A subscription to ,or additional copies of
HITACHI Service Manuals may be obtained at a nominal
charge from your HITACHI sales offices.
TUBE DISCHARGE
The line output stage can develop voltages in excess
of 25kV; if the E.H.T cap is required to be removed,
discharge the anode cap to chassis via a high value
resistor, prior to its removal from the tube.
- 2 -