American Dryer Corp. Phase 6 Microprocessor Controls ML-190HS - Manual (Page 57)

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I. Microprocessor reads “Temp Sensor Fuse.”
NOTE: Before continuing with this section check the .125 MA fuse on the computer board.
1. Replace the temperature sensor underneath the tumbler (basket) on a bracket (the bullet shaped device).
2. If it still reads “Temp Sensor Fuse,” unplug the 4 pin connector from the temperature sensor bracket.
Also, unplug the microprocessor 4 pin connector from the computer board. Where the white/red striped
wire is going into the connector, take a continuity reading across the wire and that same wire from the 4
pin connector that you unplugged earlier in this paragraph.
If there is no continuity, check for break in wire, a short to the ground, loose termination(s), or even
replace the wire.
If there is continuity, do the same thing to the black wire right next to the white/red striped wire in the 4 pin
connector.
If there is no continuity, check for break in wire, a short to ground, loose termination(s), or even replace
the wire.
If there is continuity, computer board is faulty.
a. To check temperature sensor
1) Place your digital multimeter on diode check range.
2) Place the red lead of your meter on the “black” wire of the temperature sensor and the black lead
of your motor on the white lead of your temperature sensor. At this point you should get no
response from the meter (infinite). If you get a reading the temp sensor is defective.
3) Reverse leads to temp sensor matching the black of the meter to the “black” wire of the temperature
sensor and the red of the meter with the “white” wire of the temperature sensor. At this point you
should measure approximately 1.8 V. This is the turn on voltage of the device. If you hold the
temp sensor in your hands and warm it, the reading will decrease corresponding to a higher
current flow.
4) The Phase 6 Microprocessor Controller (computer) is powered by 24 VAC on pin #12 of the J7
9 pin connector. The temperature sensor probe is a bullet shaped device that is located above the
lint basket. This temperature probe is used to sense the temperature in the exhaust of the dryer.
The temperature sensor is a two (2) terminal monolithic integrated circuit temperature transducer
that provides an output current proportional to absolute temperature. The transducer acts as a
high impedance temperature dependant current source of 1µA/ºK. The typical accuracy of this
probe is +/- 1.5º C (+/- 2.7º F). In a case where the temperature reaches 220º F (104º C), the
Phase 6 microprocessor (computer) will shut down and the L.E.D. (light emitting diode) will
display “Hot.” To restart a cycle the “CLEAR/STOP” button must first be pressed.