Hitachi HCUR700UC Service Manual page 2

HCU-R700
SAFETY PRECAUTIONS
The following precautions should be observed when servicing.
1. Since many parts in the unit have special safety-related characteristics, always use genuine Hitachi's replacement
parts. Especially critical parts in the power circuit block should not be replaced with other makers. Critical parts
are marked with
2. Before returning a repaired unit to the customer, the service technician must thoroughly test the unit to ascertain
that it is completely safe to operate without danger of electrical shock.
Check that exposed parts are acceptably insulated from
the supply circuit before returning the repaired instrument
to the customer.
• Checking method
Measure the resistance value between the both poles of
attachment cup (Power supply plug) and the exposed
parts (Parts such as Knob, Cover, etc. where the cus-
tomer is easy to touch.) and check that the resistance
value is 500 kohms or more.
in the circuit diagram and printed wiring board.
!
Insulation tester (DC 500V)
– 2 –
INSTRUMENT
(Exposed part)