Wednesday, 6 November 2019

My fantastic KSGER soldering iron arrived today - but it had some faults...

This article contains affiliate links which I may earn a small commission from. All items discussed were purchased privately.

I have been looking for a new soldering iron for a while because my old Antex 40W iron is just not powerful enough. It can't cope with soldering to large terminals or other large connectors. This can cause heat damage to the components.
T12 soldering bit
Apparently the soldering irons that use the T12 type of soldering iron bits are highly recommended. These bits are fitted internally with a heating element and a temperature sensor. This means the heat can be controlled - only the tip gets hot which is where you need it. What's more, it can get to (say) 300 degrees C in less than 10 seconds because we are not heating a load of iron and copper in the shaft and collar of the bit - it can be left in 'standby' mode at say 150 degrees C whilst you are not using it and it will shake-and-heat to 300 degrees C in 3-4 seconds.

KSGER T12 soldering station

The KSGER station has a digital display and the 'shake-to-wake-from-standby' feature - if you shake the iron as you pick it up, it wakes from standby and heats up quickly. This helps the bits to last longer.

Apparently, the only problem is that 'good' T12 bits are expensive, but the cheaper Chinese T12 bits do not last as long.

Unperturbed, I went ahead and ordered a KSGER unit from Banggood.
KSGER T12 solder station and K bit.
This has an IEC mains socket at the rear (but it does not come with a mains cable). The version I had came with a new revision of the AC-DC power board, a new version of the display panel, a metal (unearthed) case, the iron handle was all blue (no yellow) and it included one 'K' T12 bit (which is large enough to use as a shovel but not very useful for modern PCBs and surface mount components).

So I plugged it in and tested it. It heated up to 300 degrees C in about 8 seconds and easily melted my leaded multicore solder. No problem with large terminals either. It seemed to work brilliantly, but...

Fault #1

I did notice that there was an exclamation mark on the display. I found the Chinglish manual online but it was for an older version of the firmware and did not explain what the bang (!) meant.

Exclamation mark on KSGER display
I figured out that the 24 degrees C figure is the reading from the NTC thermistor which is in the handle. You can set this number as the current room temperature in one of the menus so that it can calibrate the sensor (i.e. current resistance of thermistor = 8.3K = 24 degrees C). As the thermistor reading changes, the correct reading will be displayed. Since it was set to 24 in the menu, that is what it was displaying!

So the ! seemed to indicate that the NTC thermistor was not connected (I could see on YouTube videos that if you unplugged the iron, the exclamation mark appeared). However, after disassembling the iron handle and plug, I could find nothing wrong. All the wiring seemed good and the shake sensor (a metal ball in a cage) and NTC thermistor appeared to be working fine (tested for resistance with my DVM OK).

I buzzed-out each signal, tracing from the iron to the front PCB and all seemed OK. I was baffled!

Fault #2

I had also noticed that the shake-and-wake-from-standby did not appear to work and I could not make it work by changing any of the menu options.

When I shook the iron, the ! symbol changed to a 'thermometer' symbol (which is the expected symbol when it is working correctly) and the '24' number went to a few higher numbers within a few seconds (e.g. 43...62...84) - and then the "! 24" text came back again. It still stayed in Standby though even though it had clearly detected the shake motion.

After an hour or so, it finally struck my addled brain that maybe these two faults were related. The only thing I didn't check was that the plug was wired correctly. So I found a wiring diagram on the Banggood site inside a T12 iron repair/replacement kit product listing...

KSGER Correct 5-pin plug wiring (that is not my hand!)
Sure enough the blue wire and the white wire were swapped over in the plug on my iron (is every day a Friday in China?).

Luckily, I still had my old Antex soldering iron, so I could re-solder the wires or it would have been a 'Catch 22' situation! If Banggood do reply to my Customer Support email and ask me to swap over the blue and white wires in the plug, I will tell them I can't because I don't have a working soldering iron - that's why I ordered it in the first place!

First Impressions

I have only just got it working but I really like this KSGER unit. The iron is great and can tackle larger masses of metal even with a D24 (chisel 2.4mm) or D16 (chisel 1.6mm) T12 bit fitted.

Fitting a different bit is easy, just pull out the 'hot' one with some pliers and push in the new one.

The Standby and Sleep features are very useful. It even has a Real Time Clock and coin cell battery to accurately display the current date and time. I would rather they included a mains cable and soldering iron stand however.

The internal wiring seemed to be very good and well cleaned of flux. The AC-DC PCB was directly soldered onto the rear IEC mains connector. There was one design issue which has been noted by several YouTube presenters. The coin cell battery was stuck to the top of the transformer using a double-sided sticky pad. Not only does this prevent the case from fitting together nicely, but it can't be good to heat up a battery more than you need to (I suspect this was done to decrease the risk of damage to the AC-DC power board rattling around during transportation as well as preventing the battery from being shaken loose from it's sticky pad if it was not secured by the lid). So I re-positioned the battery to the bottom of the case using a fresh double-sided sticky foam  pad.

Some people have connected a wire from the IEC mains connector earth terminal to the case chassis as well as add heat shrink and hot glue to the mains wires connected to the rear mains rocker switch. I also fitted a 3 Amp fuse to the plug so it wouldn't kill me as much as a 13 Amp fuse would ;-)

Check out the KSGER YouTube videos, but please bear in mind that the new units have been redesigned and (at least in my case) well soldered. I recommend getting a D-24 chisel tip too. Just watch out for a mis-wired iron plug!

P.S. Been using it for a few weeks now and it's great (and still working)!


  1. Well that sucks that you have to repair a brand new soldering station. There are 2 other reviews on BangGood confirming the mixed up wiring. I'm still tempted to order, but it's a disappointment.

    1. I have been using it a while now and I really like it.

  2. I got one last august and a different pencil a few weeks later. It's seen some use.. and I'm still thinking its the best deal for the money

  3. confusing me to order. does it work or not? hope years later a new generation will be work well. because i still have some T12 solder tips.