Component Testing Procedures - Amana AMH20 Service Manual

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.
Illustration
Thermal cutout
Diode
Triac
MT2
MT1 GA TE
Triac 1 (top) is for front element.
Triac 2 (middle) is for rear element.
Capacitor
Snubber assembly
Magnetron
60 HZ Models only Microwave blower
motor
50 HZ Models only Microwave blower
motor
Stirrer motor
EZCard Harness
EZCard Board
HV board to display
module wiring harness
16
!
Component
Disconnect all wires from TCO.
Measure resistance across terminals.
Control TCO ...............................................
Magnetron TCO..........................................
Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
Disconnect wires to triac.
Measure resistance from:
MT1 to MT2 ................................................
MT1 to Gate ...............................................
MT2 to Gate ...............................................
All terminals to ground................................
Measure voltage from MT1 to Gate ............... 0.8 VAC when energized. If no
Discharge Capacitor
Remove wires from capacitor terminals and
connect ohmmeter, set on highest
resistance scale to terminals.
Also check between each terminal and
capacitor case................................................
Disconnect wires to snubber.
Measure resistance across terminals............. Infinite.
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also check
between each terminal and ground.
Remove all wires from motor.
Measure resistance across coil...................... Approximately 26 Ÿ.
Remove all wires from motor.
Measure resistance across coil...................... Approximately 33.5 Ÿ.
Remove all wires from terminals.
Measure resistance from terminal to
terminal.......................................................... Approximately 29K Ÿ.
Test continuity of wires .................................. Continuity.
Insert EZCard to determine if unit can be
programmed .................................................. If unit can not be programmed, verify
Test resistance of wires ................................. Continuity.
W ARNING
Test
16023463
Results
Closed at 113° C (235° F) and open
at 66° C (150° F).
Open at 149° C (300° F) and closed
at 125° C (257° F).
Infinite resistance should be
measured in one direction and 50KŸ
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.
Infinite.
Approximately 15 Ÿ, then reverse
meter leads 30 Ÿ.
Infinite.
Infinite.
voltage, check H.V. board and wiring.
Between Terminals: Meter should
momentarily deflect towards zero
then return to over 5 MŸ. If no
deflection occurs, or if continuous
deflection occurs, replace capacitor.
Terminal to Case: Infinite resistance.
Between Terminals: Less than 1 Ÿ.
Each terminal to ground measures
Infinite resistance.
NOTE: This test is not conclusive. If
oven does not heat and all other
components test good, replace the
magnetron and retest.
EZCard harness is good. If harness
is good, replace EZCard Board.
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