d.If no voltage is present at J7 9-pin connector no. 3 to ground, then voltage should not be present at no. 5 to ground. Replace the microprocessor controller (computer).

6.Main Door Condition

NOTE: Make sure main door and lint door are closed. Also, if checking either switch, the plunger must be depressed.

a.Check L.E.D. (light emitting diode) input light “MAIN” on the component side of the computer. If the light is on, replace the computer.

b.Check voltage (24 VAC) from J7 9-pin connector no. 5 to ground. If voltage is present, check no. 6 to ground. If voltage is present, replace board.

c.If no voltage is present at J7 9-pin connector no. 6 to ground, but voltage is present at no. 5 to ground. The problem is a bad switch, bad wires or terminations J7 to J5, or J5 to main door switch.

7.“No Heat” drive and blower motors run, display reads normal (gas models).

a.Check L.E.D. input light “HT1” on the component side of the computer. If the light is on replace the board.

b.If the L.E.D. input light “HT1” on the component side of the computer is on and there is no voltage to the Hot Surface Ignitor (HSI) module “w” the display will read “BURNER CONTROL FAIL.” The problem is bad wires or terminations between microprocessor and HSI module.

c.If voltage is present on the HSI module “w” to ground. Check voltage at the gas valve if voltage is present across the two (2) “yellow” wires at the gas valve and the gas supply is on then the fault is that of the gas valve.

8.“Temp Sensor Fail Check”

a.Replace the temperature sensor underneath the basket on a bracket (the bullet shaped device).

b.If it still read “TEMP SENSOR FAIL CHECK TEMP SENSOR FUSE,” unplug J3 4-pin connector from the temperature sensor bracket. Also, unplug the microprocessor J14 4-pin connector from the computer board. Take a continuity reading from J14 no. 1 to J3 no. 1, then from J14 no. 2 to J3 no. 2.

If there is no continuity, check for break in wire, a short to the ground, loose terminations, or even replace the wire.

If there is continuity, microprocessor controller (computer) is faulty.

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ADC ML-82 service manual Main Door Condition, Temp Sensor Fail Check