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Trouble Shooting Guide

Model EL490A / EL500AZAir Purifier

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3Power does not turn on

Is the main power cord plugged in? No Plug in main power cordYes

Is the main power cord connected to the Main P.C.B.? No Connect the power cord to the Main P.C.B.Yes

Is there 120 volts AC going thru the power cord? No Replace the power cordYes

Is the fuse on the Main P.C.B. good? No Replace the Main P.C.B.Yes

Is the voltage the same both sides of the Line Filter? No Replace the Main P.C.B.Yes

Are the Main PCB foil tracings broken or component solderings open? Yes Replace the Main P.C.B.

Display P.C.B. does not work

Is the main power cord plugged in? No Plug in main power cordYes

Is the main power cord connected to the Main P.C.B.? No Connect the power cord to the Main P.C.B.Yes

Check Main PCB CN4 Connector CN4 #4 <=> #5 (both terminal voltages) : 5V DC CN4 #4 <=> #8 (both terminal voltages) : 12V DC No Replace the Main P.C.B.

YesIs the Power Switch good? No Replace the Display P.C.B.

YesIs voltage of Micom #9 pin on Display PCB around 2.0~2.6V DC? No Replace the Display P.C.B.

YesAre the Display PCB foil tracings broken or component solderings open? Yes Replace the Display P.C.B.

NoIs Micom #1pin on Display PCB 5V DC? Yes Replace the Display P.C.B.

The Odor Sensor does not work

Was power on for over 4 minutes? No Turn power on for over 4 minutes and recheck sensorYes

Is the Sensor opening dirty Yes Clean the Sensor openingNo

When you touch the gas sensor by hand, can heat be detected? No Replace Odor Sensor

YesAre the Display PCB foil tracings broken or component solderings open? Yes Replace the Display P.C.B.

NoCheck voltage change after checking Micom #2 pin. FYI voltage of sensor is around 0.7V DC under clean environment. No Replace the Display P.C.B.

4The Dust Sensor does not work

Was power on for over 4 minutes? No Turn power on for over 4 minutes and recheck sensorYes

Is dust sensor connected to the Display P.C.B.? No Connect the Sensor to the Display P.C.B.Yes

A open Magic Marker type pen is placed next to the Dust Sensor opening. Does the voltage of CN1 pin 15 rise? No Replace the Display P.C.B.

YesAre the Display PCB foil tracings broken or component solderings open? Yes Replace the Display P.C.B.

NoCheck voltage change after checking Micom #2 pin. FYI voltage of sensor is around 0.7V DC under clean a environment. Yes Replace the Display P.C.B.

The Alarm (Beep) is not heard

Is outer appearance of the buzzer normal? No Replace the Display P.C.B.Yes

Are the Display PCB foil tracings broken or component solderings open? Yes Replace the Display P.C.B.

NoWhen checking MICOM pin #4 is the voltage is measured around 0.2-3V DC? No Replace the Display P.C.B.

The Fan Motor does not run

Is the main power cord plugged in? No Plug in main power cordYes

Is something stuck in the motor fan? Yes Remove the obstruction.No

Are the motor electrical connections at the motor connected correctly? No Correctly connect the electrical connections.

YesAre the motor electrical connections at the Main P.C.B. connected correctly? No Correctly connect the electrical connections.

YesDo VM(DC310V Red wire), VCC (DC15V yellow wire), VSP (DC 0~6.8V blue wire) come out at fan speed adjuster? No Replace the fan motor

YesWhen measuring voltage of white (#6 pin) connected to Motor connecting connector CN2, it is about DC2.5V while fan is working? No Replace the Display P.C.B.

YesIs the fan motor bad? Replace the fan motor

5Plasma Doctor does not work.

Is the Plasma Light Lit? NoTurn the power on by holding the power button for 3 seconds.

YesAre the Plasma Doctor wires connected correctly to the Main P.C.B.? No Connect the wires to the Main P.C.B. correctly.

YesIs 7 pin voltage of connector CN1 of Display PCB connected to Main PCB 5V DC? No Replace the Display P.C.B.

YesIs the output voltage at CN5 of the Main P.C.B. the same as the output voltage(120 volts AC)? No Replace the Main P.C.B.

YesIs there a discharge noise heard from the Plasma Doctor? No Replace the Plasma Doctor.

YesRepeat ION measuring. Go back to step 1?

Remote Control does not work.

Is the main power cord plugged in? NO Plug in main power cordYes

Are the remote batteries good? NO Replace batteriesYes

Measure voltage of Micom 12 on the Display PCB. Voltage while the remote is working should be around 1V DC. No Replace the Display P.C.B.

YesAre the Display PCB foil tracings broken or component solderings open? Yes Replace the Display P.C.B.

NoReplace the Display PCB due to faulty Micom.

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Cauton: Reassembly in reverse order of diassembly.

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