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