Amana RC17S2 Service Training Manual page 30

Component Testing Procedures
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
l l I s u r t t a o i n
MT2
MT1 GA TE
Triac 1 (center)
Triac 2 (left)
Triac 3 (right
!
C o m p o n e t n
Thermal cutout Disconnect all wires from TCO.
Measure resistance across terminals.
Magnetron TCO ....................................
Cavity TCO ........................................
Diode
Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
Triac Resistance Check
Disconnect wires to triac.
Measure resistance from:
MT1 to MT2 ........................................
MT1 to Gate .......................................
MT2 to Gate .......................................
All terminals to ground ..........................
Voltage Check
Measure voltage from:
MT1 to Gate
Capacitor Discharge Capacitor
Some units may use Remove wires from capacitor terminals
more then one type of and connect ohmmeter, set on highest
capacitor. Refer to resistance scale to terminals.
Parts Manual for
correct capacitor
quantity.
Also check between each terminal and
capacitor case.
Snubber assembly Disconnect wires to snubber.
Measure resistance across terminals ........
Magnetron
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also
check between each terminal and ground.
Blower motor Remove all wires from motor.
(Prior to S/N 1107101263)
Measure resistance across coil.............................
Blower motor Remove all wires from motor.
( Starting at
S/N 1107101263 and after)
Measure resistance between:
Orange and white terminals ......................
Yellow and white terminals ........................
WARNING
T e t s
28
R s e u s t l
Open at 300 °F (149 °C) and
closed at 257 °F (125 °C)
Opens at 262 °F (128 °C)
In nite resistance should be measured
in one direction and 50K Ω or more in
the opposite direction.
NOTE: Ohmmeter must contain a
battery of 6 volts minimum.
Caution - Do not operate oven with
wire to terminal MT2 removed.
In nite
Approximately 60 Ω
In nite
In nite
0.8 VAC when energized. If no
voltage, check H.V. board and wiring.
Between Terminals: Meter should
momentarily de ect towards zero then
return to over 5 M Ω. If no de ection
occurs, or if continuous de ection
occurs, replace capacitor.
Terminal to Case: In nite resistance
In nite
Between Terminals: Less than 1
Each terminal to ground measures
In nite resistance.
Note: This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
Approximately 25 Ω
Approximately 31 Ω
Approximately 29 Ω
Ω