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Insects/Mosquitoes E-killer Saved From Waste Dump

By on October 13, 2021







This Hongjian mosquitoes killer was brought to me by a neighbour with complaint of not working. Few months ago, it was repaired changing LEDs only.


Now back on my work bench. I did troubleshoot, found the non-polar caps & LEDs are dead and I couldn’t get the values, sizes from store.
The picture of the original board below:
mosquito killer circuit board
So I decided to build another circuit for it, googled on internet how to DIY on mosquitoes killer which I located one.
However the caps for this DIY are bigger in size than original ones, so I thought of  modifying it. I bought all components for building DIY, soldered all on a small sized bread board, following instruction, picture below:
mosquito killer parts
However,circuit board couldn’t fix into original case,so I used a discarded table lamp base(red colour), then connected it to original case (white & green colour).Connected A/C cord to it, having removed original switch. Now it’s moment of truth!!.
Plugged completed DIY into A/C socket, put housefly into it, see what happens, electrocuted with smoke!! Picture below(zoom to see smoke):
fly killed by mosquito killer
I measured voltage at iron mesh terminals: 700 Volt, very high and dangerous!! Well, my neighbour was happy and mosquitoes are again in trouble.

Please keep children away from such appliance and best use at night. This is picture of finished repaired work below:

how to fix a mosquito killer circuit board

fixing mosquito killer board

imoudou onwuwah

This article was prepared for you by Imoudu Onwumah from Nigeria. He is 62 years old and has just 3 years experience in electronics repairs. I started career in hotel industry as a chef, but then I was doing repairs only in electrical repairs as a  hobbyist. In 2018, I decided to learn about electronics which through Jestine’s electronics e-books and holding my hand, am an electronics  techie today.

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Note: You can read his previous article on Suoer Digital Meter Repair




  1. Albert van Bemmelen

    October 13, 2021 at 4:59 pm

    Nice rework job of this old not working generator circuit! I made some time back a small dangerous taser-like HV-generator. And found a very good task for it by killing many small tiny flies that invade my home and my plants and apparently are attracked to coffee pads. I zapp them in the HV spark that pulsates between the 2 electrodes which immediately kills them and pulls them to these metal pins. Like the module that was used in this instructables:

  2. Babu M S

    October 13, 2021 at 10:12 pm

    Good job done.Thank you very much for sharing.

  3. Parasuraman S

    October 14, 2021 at 11:20 am

    Vow! That was a real determined work with satisfying results! Well done!

  4. Yogesh Panchal

    October 14, 2021 at 3:44 pm

    Imoudu Onwumah,
    Good Attempt of repair and congratulations! for reviving the equipment.

  5. Imoudu Onwumah

    October 14, 2021 at 11:05 pm

    Mr Albert.V.B & Mr Bebu.M

    Thanks very much. Infact I had to construct another one with sponge case for myself because of mosquitoes in my area,working perfectly.

  6. Imoudu Onwumah

    October 14, 2021 at 11:08 pm

    Mr Parasuraman.S & Mr Yogesh.P

    Thanks for your comments.

  7. Waleed Rishmawi

    October 18, 2021 at 1:52 pm

    a job well done on the reviving of the unit. thanks for sharing and have a blessed day

  8. Humberto

    November 2, 2021 at 10:13 pm

    Good idea re-constructing this device with a new schematics.


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