CXG 936D digital soldering iron – Teardown and Review - Page 1
Forum section: electronics / general

author: ciccio
author_rank: Frequent Contributor
timestamp: October 11, 2017, 12:37:14 pm
content: I bought this digitally adjustable soldering iron from Banggood for the ridiculous price of 12.37 Euros, including delivery.I've plenty of soldering irons and stations, but this was bought as a gift for a young student.I've ordered another model, with backlighted display, but it was out of stock , so I selected this one.Now I do not see it anymore on Banggood site, but there are plenty of similar units at similar prices.After receiving the unit, I remembered seeing the same iron in one video by Mike's Electronic Stuff, where he shows his toolbox' irons.The iron is made by a Company named Shentzen CGX Electronic industrial Co. Ltd (www.cgx.cn).I never heard of them, but their site is FULL of soldering equipment, including any HAKKO clone you may think of (did you ever though about a green clone? They have it, and many other colours…)They have even a series of different power High Frequency soldering stations, with two displays: one on the station an one in the handle (model XG200, photo, and others). What are two displays for? I did not understand, but two is better than one…Their English is a little Chinglish, including the box printing: what is a NC thermostat soldering station – Condensed (?) version???The user manual ( a two page sheet) is not clear in many points, and describes an adjustable Sleep Timer that I was not capable to access, but what do you want for such a price??In any case, this is a brief description of the operation and a very short teardown.Two button allow to change the temperature setting. The set point is displayed in a small LCD. It is possible to switch from °C to °F by pressing the two buttons.When the heater is ON a decimal point at the rightmost corner of the display is visible..It is possible to offset the display to compensate for sensor error, but my unit was well calibrated (as verified with a tip thermometer) and I did not test this feature.It uses standard HAKKO clone tips and ceramic heater.The supplied tip is a very fine conical one.Heating time was fast (27 second to reach 370 °C starting at 20 °C) and the tip temperature was stable during continuous use.The handle has a comfortable rubber grip and the unit is lightweight.The mains cable is very thin and flexible. It is marked as a 3 x 0.5 square mm, but it seems too thin. .. I'm not sure it will pass a certification test.The same for the big red capacitor on the PCB: I think it is used in the voltage dropper that powers the circuit, but I could not verify if it is a X or Y type. A standard film type can fail and destroy all the components (I did not notice any fuse on the board).On the inside there is a dual sided PCB, with the display, a 16 pin microcontroller : an STC 12C520xx (I could not read last two digits) , an LM258 dual op-amp, a MOC3020 triac driver optocoupler and a BT134 4 Amp triac, plus other componentsSoldering quality is excellent, as is excellent the general build quality.Even the included support, made with thin sheet metal is very well finished (albeit totally useful in real use).I must admiti that I'm really satisfied with the results: this cheap tools beats my middle price irons: I can buy a new one for the price of two spare Weller or JBC tips...

author: narpat007
author_rank: Newbie
timestamp: May 01, 2019, 11:16:14 am
content: Hi !Thanks for posting the teardown.what is this component which looks like a regular resistor ? I have this soldering iron and display is not working nor the element getting heated. I measured the value of ohms of this component abd it is showing 36Mega Ohm, very strange !

author: ciccio
author_rank: Frequent Contributor
timestamp: May 01, 2019, 12:19:41 pm
content: Hy,there was another thread in this forum about a not working iron of the same series (if I remember well, it was the 90W one).The user had the same problem, and that resistor was open.He asked for the value, I and other answered, but now I cannot retrieve the thread. As soon as possible I will look again and post a response.Edit:I've found the thread.https://www.eevblog.com/forum/profile/?area=showposts;u=9522The resistor is 82 ohms, 1/2 W.Hope it will work for you.Best regards

author: narpat007
author_rank: Newbie
timestamp: May 04, 2019, 12:11:33 pm
content: Thanks a lot, will try.