Panasonic NN-T221MB, Service Manual

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1 Inverter Warning
The inverter board looks like a normal printed circuit board.
However, this printed circuit board supplies the magnetron tube
with very high voltage and current.
The inverter PCB:
1. Produces very high voltage and current.
2. Has an Aluminium heat sink which becomes very hot.
3. Has capacitors in the circuitry that hold a high voltage
charge even when the oven is not operating.
Do not
1. Do not touch the high voltage circuitry. When replacing
the board take extreme care to avoid possible electric
shock.
2. Do not touch the aluminium heat sink as it is part of the
high voltage circuit and becomes very hot.
3. Do not attempt to repair the inverter PCB as this can be
very dangerous. Replace the high voltage, inverter circuit
as a complete unit.
4. Do not adjust or tamper with the pre-set volume on the
inverter board. It is very dangerous to adjust this pre-set
without proper test equipment.
5. Do not operate the microwave oven when the inverter
grounding plate and fixing screw is loose. It is very dan-
gerous to operate the inverter circuit board with out a
proper ground connection.
Inverter Power Supply Diagram
Figure 1
Inverter Layout
Figure 2
2 FEATURE CHART
FEATURES NN-T221MB
Microwave 6
Weight Defrost 3
Weight Reheat 2
Weight Cook 1
Stage Cooking 3 Stage
Delay Stand Yes
Kg > Lbs/oz Yes
Clock 12 Hours
Word Prompt English