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Resolved “OP” Error Due To A Design Problem In KADA 2018 D+ Soldering Work Station

By on June 25, 2023
kada solder station repair





kada station solder repair

My Kada 2018 D+ was giving me an error problem of ‘OP’ in the soldering iron and even after checking for any loose contacts of the sensors or dry solder in the unit, I could not find any, though I did retouch all possible places on the board. Then I published my problem in the Whatsup technical group and in came a help from one technician who could successfully trouble shoot the real reason and resolve it.

Before I disclose the reason and solution, let us have a look at the inside of this SMD Work Station and the structure of soldering iron:

kada 2010+ solder iron repair

how to fix a kada solder iron

how to fix kada station solder

The heating element along with sensor is fit on a PCB which has elevated sides to seat in a slot on the handle, as can be seen from the above pictures. Pins 1 & 2 are for the heating elements while 3 & 4 are for the sensors. The pin 5 is the earth point which is connected to a spring that grounds the metal housing. After switching on the soldering iron, if we push the cable in by hand, the ‘OP’ disappears and the element starts getting heated up. If we release the hand, once again the OP appears. Due to a design problem, the heating element was not sitting deep enough inside the soldering bit, because of which the sensor was not able to detect presence of a bit.

Like in induction cooker, if a vessel is not placed properly on top, the error code appears, because the sensor does not detect a conducting material on top, the sensor of this iron that is housed inside the porcelain element unit, do not get the presence of the bit, because of which the uController gives this error code. Incidentally, there was no explanation of this ‘OP’ in their manual! And this is exactly what my techie friend told me. In fact, I wondered how he ever found it out! The solution done by him was grinding the insert and allowing the bit to slide in more. But that calls for a lot of trial and error adjustments before it seats in properly. So, what I did was soldering two rings on the PCB, just beneath the elevations, so that the PCB would not get pushed in fully by the spring. You can perhaps follow my explanation better with the following pictures:

how to fix and repair kada soldering station iron

By this improvisation, the PCB is held a bit above so to enable proper insertion into the bit. This solved the ‘OP’ error problem and the iron worked very well, bringing a big relief! As you all will agree, proper functioning of all our tools is a must for our type work.

how to fix a broken kada 2018+ soldering station iron

Some of you might ask why did I use soldering type of insertions at that point and would it not melt and give away, when the iron gets hot. The doubt is genuine, but let us remember that they have used a PCB, which never got burnt. That is because of the non-conducting paste that holds the element to the PCB.

So, curtain fell on this issue and I am ever indebted to the techie friend, whom I have never even met, for resolving what looked like a perennial problem. Satisfaction impregnated with a lot of relief found its way to the collection!


This article was prepared for you by Parasuraman Subramanian from India. He is 72 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.

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  1. Albert van Bemmelen

    June 25, 2023 at 3:38 pm

    After reading your present Kada 2018D+ repair I remembered your previous Soldering Work Station T-12X repair with neglected earth issue that blew a mosfet.
    Luckily you were able to fix both issues professionally like always because proper functioning of all our tools indeed is a must for our type work.
    I sincerely hope that my mini Quecoo OLED T12-942 Quicko heating soldering station with the easy exchangeable T12 soldering irons with different available tips never shows such issues. And my cheaper Quicko T12-942 station uses an external 24V 5A power adapter. As only the more expensive Quicko soldering station models use an integrated power supply.

    • Parasuraman S

      June 25, 2023 at 4:00 pm

      Many thanks for your comments and details of other soldering irons.

    • Hollis LuQuette

      June 25, 2023 at 4:23 pm

      Albert , most of the T-12 soldering stations don't have a good earth ground , I have a KSGER and it too had a earth issue .... I fixed that right away when I got mine.... There are videos on you tube to modify the issue ....

      • Parasuraman S

        June 25, 2023 at 4:58 pm

        Thanks for the info!

      • Albert van Bemmelen

        June 25, 2023 at 5:26 pm

        Thanks for letting me know Hollis. Although my plastic cased 24V 5A power supply is external and the adapter therefore only requires a 2 pole flat ungrounded (German) Euro 230VAC plug anyway without any earth wire.

        • Parasuraman S

          June 25, 2023 at 6:52 pm

          Yes, that looks like a safe device!

  2. Waleed Rishmawi

    June 26, 2023 at 7:10 pm

    I had KadXa the older model and it did not give me any issue for about ten years then it started to act up and I did not bother to get it fixed because I bought it off ebay for 80 dollars. I up graded my soldering iron to Hakko FX-951 and so far I have no issue with it. thanks for sharing your repair and have a blessed day

    • Parasuraman S

      June 27, 2023 at 12:30 am

      Many thanks for your comments and sharing your wonderful experiences, my dear friend!

  3. Yogesh Panchal

    June 28, 2023 at 12:24 am

    Excellent! Sir.

    • Parasuraman S

      June 30, 2023 at 3:50 pm

      Many thanks, dear!

  4. beh

    June 28, 2023 at 4:08 pm

    Indeed it is interesting article . I want to recommend you to send this article to the manufacture of this soldering work station and show them how to resolve the problem of their product this easily . and ask them for reward of course.

    • Parasuraman S

      June 30, 2023 at 3:52 pm

      It is a Chinese product! I don't think there is any use in sending such a report! I have done that in the past and did not get any response; leave alone the reward! (LOL) Many of these guys cannot follow English! That is the problem! Many thanks for your comments and advice!

      • Beh

        July 1, 2023 at 3:40 pm

        yes this is true. last time when i was reparing the mother board of sony TV the psu was made by Sanken co. in Indonesia and i found their email address via their site i wrote a letter and ask them for help and diagram but no one answerd me. i think the main reason was they do not know English langugge enough that is why they did not answered to me. same thing is possible in china

        • Parasuraman S

          July 3, 2023 at 5:18 pm

          Yes, it looks like that! Moreover, they might be receiving hundreds of emails and they pick up only random for response.


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