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A Cool ULTERA Sonic Humidifier Transducer Steamer Repair (Brand Name-Goal)

By on May 10, 2021
Transducer Steamer Repair

goal transducer steamer repair

One time more another invention from Chinese market appeared on my workshop desk for repair.

oscillator board repair


The problem of machine was not producing the cold steam and was dead but the red LED on the panel was On and this indicate that the power is coming in but machine would not function! How this machine works?

The most important part of this machine is the membrane of a piezo electric that by the help of a strong transistor ( in my case BU406  )and one coil and a capacitor make an oscillator and these oscillation waves appear on the membrane of piezo electric and membrane starts to vibrate in a very high speed and due to this speed the molecules of water starts to break down from each other’s and start to come up from the surface of water. A mass of molecules looks like a steam but is not hot steam but is cool steam of water, a fan is employed to move the steam from the surface of water up to the outside. The machine has a power supply (SMPS) and like any other similar Power Supply it contain all major parts. In my case the power supply produce two output voltages 32v and 12v.

steamer oscillator board




The 12 volts is just for running the fan of the machine and 32 volts for running the oscillator board. My main problem was the voltages were lower than normal- 12 volts was 8 volts and 32 volts was  21 volt. I started to find out why the voltages were not sufficient actually I did find nothing at all, the parts were intact and the power supply board there were two electrolytic capacitors in the output stage but the PEAK ESR70 tester read these two caps with good ESR and the capacitance was within the tolerance value.

The bigger one was 330 micro@50 volts with commercial name of TEAPO, the smaller one was  470micro@25 volt with commercial name FUJY.  I consulted with one of  repairer friends about this case, he asked me to replace both caps regardless of the fact that both were checked good. I told him these two were checked and were healthy but he insisted that I direct replaced both capacitors. I did and the voltages were returned to normal!


BU 406

fan of machine

Fan of Machine

Another problem that I had with this machine was bad BU406. this is a power transistor NPN 7 watt 200 volts that was not working. This transistor function is to cause the main motor to produce strong pluses to run the oscillator and therefore the membrane of piezo of machine start to vibrate, unfortunately in the market I could not find the original transistor even the Atlas DCA PRO 75 detect these transistors good but in circuit did not work.

Finally I found an original transistor and by replacing the transistor the machine started to work. I compared both the BU406 transistor with ATLAS Pro 75. One was original and the other was Chinese made BU406 and there were some differences in the result and this was my problem!

power supply steamer transducer repair


Another problem was surprisingly and confusingly Chinese manufacturers made this machine without observation of international color codes for wiring, the yellow wire in this machine was as ground and black wire as hot +12 volts. By right yellow wire should be +12 volt and black wire should be ground.

how to fix transducer steamer

Finally, machine start to produce the cool steam and steam is visible.

beh new

This article was prepared for you by Mr Beh from Iran.

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  1. Parasuraman S

    May 10, 2021 at 12:12 pm

    A good steaming work! Well done! Many thanks for sharing!

  2. Waleed Rishmawi

    May 10, 2021 at 3:39 pm

    I never heard of cold steam because these two words contradict each it more like a vapore?

  3. Albert van Bemmelen

    May 10, 2021 at 4:21 pm

    I really liked your article and good explanation! I wondered however about the bad functioning PEAK ESR70 meter. And also about the PEAK Atlas DCA PRO 75 that also failed to correctly disapprove of the China made 'fake' BU 406 transistor. I think that a similar article about this conclusion was also published on this blog? Maybe you now also can check both transistors in the DY294 transistor tester to find out what makes the fake transistor bad? That probably whould solve this interesting question.

  4. Yogesh Panchal

    May 12, 2021 at 3:46 pm

    Good Job!
    Some time Components reading showing OK but Some components behave differently under actual Load hence don't relay On Meters.


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