6
Microwave service manual – Model:
microMD UK
Service information
Tools and measuring instruments
Necessary tools
Tools normally used for TV servicing are sufficient.
Standard tools are listed below.
• Diagonal pliers
• Long nose pliers
• Phillips screwdriver
• Flat blade screwdriver
• Wrench (size 5mm)
• Nutdriver (size 5mm)
• Adjustable wrench
• Soldering iron
• Solder
• Vinyl insulation tape
• Polishing cloth
Necessary measuring instruments
• TESTER (VOLTS-DC, AC., Ohmmeter)
• Microwave survey meter
- Holaday HI-1500, HI-1501
- Narda 8100, 8200
• Inch scale
• 600 cc non conductive material beaker
(glass or plastic), inside diameter:
approx. 8.5 cm(31/2 in.)
• Cylindrical and made of borosilicate glass vessel.
max. thickness: 3 mm
outside diameter: approx. 190mm
height: approx. 90mm
• Glass thermometer: 100°C or 212°F (1 deg scale)
Microwave leakage test
Cautions
• Be sure to check microwave leakage prior to
servicing the oven if the oven is operative prior
to servicing.
• The service personnel should inform the
manufacture importer, or assembler of any
certified oven unit found to have a microwave
emission level in excess of 5 mW/cm
2
and
should repair any unit found to have excessive
emission levels at no cost to the owner and
should ascertain the cause of the excessive
leakage. The service personnel should instruct
the owner not to use the unit until the oven
has been brought into compliance.
• If the oven operates with the door open, the
service personnel should:
- Tell the user not to operate the oven.
- Contact the manufacturer.
• The service personnel should check all surface
and vent openings for microwave leakage.
• Check for microwave leakage after every
servicing. The power density of the microwave
radiation leakage emitted by the microwave
oven should not exceed 4 mW/cm2. Always start
measuring of an unknown field to assure safety
for operating personnel from radiation leakage.
Measuring microwave energy leakage
• Pour 275±15cc of 20±5°C(68±9°F) water in a
beaker which is graduated to 600 cc, and place
the beaker on the centre of the turntable.
• Set the energy leakage monitor to 2450
MHz and use it following the manufacturer’s
recommended test procedure to assure correct
result.
• When measuring the leakage, always use the 2-
inch (5cm) spacer supplied with the probe.
• Operate the oven at its maximum output.
•
Measure the microwave radiation using an
electromagnetic radiation monitor by holding
the probe perpendicular to the surface being
measured.
Move probe along shaded area
Probe scanning speed
Less than 2.5 cm/sec
(1in/sec)
