Service Points - Hitachi HA-6800 Service Manual

HITACHI HA-6800
• Removing the printed wiring boards
• Ausbau der leiterplatten
• Deposer des plaquette"s
a
circuit imprime
Plastic
rivet
Fig. 2
Abb.
2
Fig. 3
Abb. 3
SERVICE POINTS•WARTUNGSPUNKTE•POINTS DE SERVICE
• As this unit uses a large capacity power supply,
be careful of the following points when check-
ing and repairing.
( 1) To check and repair the printed wiring boards, be
sure to cut off the power and pull out the power
cord. Remove the bottom plate and discharge the
power capacitors by touching it with a resistor of
approx. 10 ohms, 5 watts capacity at the positions
C816 and C817.
(2). Do not touch the terminals of nearby parts with a
DC voltmeter when connecting it for adjusting the
idle current as malfunction may result. Handle the
DC voltmeter carefully. Wind insulating tape
around the screwdriver.
-4-
(3) This amplifier employs a heat loop and so when
conducting a continuity check, the unit should be
placed horizontally or stood on its transformer
end.
• Parts installation method
Great care is taken in installing parts to improve the
safety of products. For example, parts are covered
with tubes, or they are kept away from the printed
wiring board surface. Be sure to maintain the
previous conditions after replacing parts for repair.