Hitachi I 48 Service Manual

Page 2

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SAFETY PRECAUTIONS

WARNING: Since the chassis of this receiver is connected
to one side of the Mains Supply during operation, service
should not be attempted by anyone unfamiliar with the
precautions necessary when working on this type of
equipment.

The following precautions should be observed:

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 handling.

When service is required, an isolation transformer
should be inserted between power line and the receiver
before any service is performed on a "HOT" chassis
receiver.

When replacing a chassis in the cabinet, always replace
all the protective devices are put back in place, such as;
barriers, non-metallic knobs, adjustment and compart-
ment cover or shields, isolation resistor-capacitor, etc.
When service is required, observe the original lead

dress. Extra precaution should be taken to assure
correct lead dress in the high voltage circuitry area.
Always use the manufacturer's replacement com-
ponent. Especially critical components as indicated on
the circuit diagram should not be replaced by other
makes.

Furthermore where a short circuit has occurred,
replace those components that indicate evidence of
overheating.

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 instrument by the
manufacturer has become defective, or inadvertenly
defeated during servicing.

Therefore, the following checks are recommended for
the continued protection of the customer and service
technician.

CONTROL

TELESCOPIC ANTENNA
VHF PRE-SET FINE TUNING
VHF CHANNEL SELECTOR
UHF FINE TUNlNG

UHF CHANNEL SELECTOR
CONTRAST

BRIGHTNESS
SLEEP TIMER
LOOP ANTENNA

95°9799"?wa

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ON-OFF SWITCH, VOLUME CONTROL

11. UHF ANTENNA TERMINAL

12. VHF ANTENNA TERMINAL

13. VHF ANTENNA EXT.-lNT. SWITCH
14. POWER RECEFTACLE

15. H. HOLD

16. V. HOLD

17. V. LINEARITY
18. V. SIZE

19. EARPHONE JACK