NEC MultiSync 75F-3 Service Manual page 5

c) Reverse the AC plug at the AC outlet and repeat the steps for AC voltage measurements for each
exposed metal part.
d) Voltage reading must not exceed 0.3 volts RMS, equivalent to 0.2 milliampere AC. Any value ex-
ceeding this limits ill constitute a potential shock hazard and must be corrected immediately
1-1-1 Product Safety Notices
Many electrical and mechanical parts in this chassis have special safety-related characteristics which are
often not evident from visual inspection. The protection afforded by them may not be obtained by replac-
ing them with components rated for higher voltage, wattage, etc. Before replacing any of these
components, consult the Recommended Spare Parts List given at the end of this manual. Any of the
replacements that do not provide the same safety characteristics may result in shock, fire, X-ray emission
or other hazards.
1.2 Servicing Precautions
Warning: An electrolytic capacitor installed with the wrong polarity might explode.
Caution: Before performing servicing covered by this service manual, read and follow the Safety Precau-
tions section of this manual.
Note: If unforeseen conflict between the following servicing precautions and of the safety precautions,
always follow the safety precautions
1. Follow closely the servicing precautions printed on the monitor cabinet and chassis.
2. Always unplug the AC power cord from the AC power source before removing or installing any compo-
nent or assembly, disconnection PCB plugs or connectors and connecting a test component in parallel
with a capacitor.
3. When replacing parts or circuit boards, clamp the lead wires around the unit before soldering.
4. When replacing a high wattage resistor (>0.5W metal oxide film resistor) in the circuit board, keep the
resistor about 1 cm (1/2 inch) away from the circuit board.
5. Keep wires away from the high voltage or high temperature components.
6. Keep wires in their original positions so as to minimize interference.
7. Always connect a test instrument's ground lead to the instrument chassis ground before connecting the
positive lead; always remove the instrument's ground lead last.
Figure 1-1. Set Up For AC Leakage Current Check
To known
Earth ground
1500 ohm 10 watt
To exposed metal
Cabinet part
0.15ufd
2