Brand New KSGER T12 Glowing Red

[ABSTA]

Hi friends


I just received my KSGER T12 Solder Station.

When i turned on ,it was mentioning error on the screen.

after few seconds The tip get glowing red until i unplug the station .

The tip is okay, i tried it with multimeter on beeper mode.

i hope to find some help with you please

[CaptDon]

Looks like the thermal control device (scr, triac, thermostatic switch) is shorted.
I am not familiar with the make and model. Chinese?? Good Luck or should we
say Good Ruck.

[Manul]

I imagine the tip material to be damaged by such heat. So it will not be a good soldering tip anymore. Also possibly temperature sensor and heating element may have experienced some damage. Would be best to return to seller for these reasons alone if possible. If there is no other way and you need to fix that, look how the current to heating element is controlled. Something is probably shorted, like CaptDon said above.

[ABSTA]

Looks like the thermal control device (scr, triac, thermostatic switch) is shorted.
I am not familiar with the make and model. Chinese?? Good Luck or should we
say Good Ruck.

yes it's a chinese Model  :-[
Yes it seems to be a faulty controller... i will try to find the shorted component ...

So it begins with Testing : Scr,Triac ans the thermostatic switch :-)

thanks to your help ...

if anyone knows this station ?

[Manul]

I do not know this station, but schematic looks simple. Also found another schematic on the net, it is not exactly like what you posted, but basic structure is same. So it seems Q1 (P-ch mosfet TPC8107) is driving heating element and Q2 is driving Q1.

[wraper]

It should be MOSFET, not triac since KSGER uses SMPS.

[ABSTA]

It should be MOSFET, not triac since KSGER uses SMPS.

Hey

I traced some pins of the MOSFET

it seems to be an ao4354

AND All pins are shorted to the + side

there is a sample of my tarces whith multimeter (beeper mode)

[ABSTA]

 

[Manul]

it seems to be an ao4354

?? I see AO4409.

[Manul]

If I would change it, I would choose something more trustful like IRF9321 for example. Also Vishay makes some nice mosfets.

At least good news is that it is p-ch mosfet driven by Q2, so MCU PWM pin should not be damaged. Should be replace and go situation.

[ABSTA]

it seems to be an ao4354

?? I see AO4409.

Yes ,sorry i was wrong its an ao4409 ,

How to make sure it is faulty? ( how i can mesure it with multimeter )

Thank you ...

[Manul]

With what you measured with beeper mode it is pretty much guaranteed to be faulty. Also it agrees with the symptoms of heating element beeing on full power all the time. There is not much else to do, just to find a replacement and perform a quality soldering, while taking some care to not damage new one with static electricity (do not wear synthetic clothes for example).

[floobydust]

I drew a KSGER T12 STM32 controller V2.1S schematic here:
https://www.eevblog.com/forum/reviews/t12-stm32-v2-1s-soldering-station-controller-schematic-etc/msg2463234/#msg2463234
it looks the same as what you have OLED-V3.0 but different designators. I'm not sure what R0 is for.

AO4409 is rated 15A 30V and 20V on the gate, and the power supplies are usually 25V, so not much margin for spikes. I add a diode across the heating element. My controller had TPC8107 which has a gate zener.
The driver Q2 is also a mosfet, so check that it is not shorted D-S as well.
Your power connector has bad solder joints and not sure why it's on the front side. Those JST connectors aren't really rated for 3A so people just hardwire it.

[ABSTA]

I drew a KSGER T12 STM32 controller V2.1S schematic here:
https://www.eevblog.com/forum/reviews/t12-stm32-v2-1s-soldering-station-controller-schematic-etc/msg2463234/#msg2463234
it looks the same as what you have OLED-V3.0 but different designators. I'm not sure what R0 is for.

AO4409 is rated 15A 30V and 20V on the gate, and the power supplies are usually 25V, so not much margin for spikes. I add a diode across the heating element. My controller had TPC8107 which has a gate zener.
The driver Q2 is also a mosfet, so check that it is not shorted D-S as well.
Your power connector has bad solder joints and not sure why it's on the front side. Those JST connectors aren't really rated for 3A so people just hardwire it.

Q2 Isn't short

i tried to measure VOLTAGE between drain and source of the mofset and i don't find Any 24v,20v or 30v
i put it off the circuit , and (maybe i did a mistake) when i turn on the station she seems to works and displays "INVERT"

its definitely a faulty MOSFET

to close the topic , please ,where i can find a website to order it (shipping to France) and what are the other transistors  equivalent to this one

[Mp3]

I drew a KSGER T12 STM32 controller V2.1S schematic here:
https://www.eevblog.com/forum/reviews/t12-stm32-v2-1s-soldering-station-controller-schematic-etc/msg2463234/#msg2463234
it looks the same as what you have OLED-V3.0 but different designators. I'm not sure what R0 is for.

AO4409 is rated 15A 30V and 20V on the gate, and the power supplies are usually 25V, so not much margin for spikes. I add a diode across the heating element. My controller had TPC8107 which has a gate zener.
The driver Q2 is also a mosfet, so check that it is not shorted D-S as well.
Your power connector has bad solder joints and not sure why it's on the front side. Those JST connectors aren't really rated for 3A so people just hardwire it.

Q2 Isn't short

i tried to measure VOLTAGE between drain and source of the mofset and i don't find Any 24v,20v or 30v
i put it off the circuit , and (maybe i did a mistake) when i turn on the station she seems to works and displays "INVERT"

its definitely a faulty MOSFET

to close the topic , please ,where i can find a website to order it (shipping to France) and what are the other transistors  equivalent to this one

You can't return the KSGER to the seller or have them compensate you?

TME in poland seems good, i ordered from them recently.

[BreakingOhmsLaw]

Holy shit, you should really consider to get something more reputable. Thermal runaway protection is no small issue, and the lack thereof seems a design flaw. That said, i'm not sure the likes of Weller and other major brands have runaway protection, but i've yet to read or hear from red-hot tips on quality solder stations.
Point in case is: you will *never* be able to leave this puppy unattended, even for just minutes, even if you get it replaced.
Better spend a couple of bucks more, perhaps on a used brand name unit than to burn down your house. That's just scary. Good luck mate.

[Manul]

to close the topic , please ,where i can find a website to order it (shipping to France) and what are the other transistors  equivalent to this one

You can choose IRF9317PbF, IRF9321PbF they should be ok and even better then original. In Europe I recommend Farnell.

[wraper]

Holy shit, you should really consider to get something more reputable. Thermal runaway protection is no small issue, and the lack thereof seems a design flaw. That said, i'm not sure the likes of Weller and other major brands have runaway protection, but i've yet to read or hear from red-hot tips on quality solder stations.

None of them have. And basically any other station will do the same if pass element fails short. Particularly Hakko 951 will glow red if triac fails as it uses the same cartridge.

[Ian.M]

If a station has a beeper and is MCU controlled, it would be fairly simple to have the firmware do some tests on initial powerup and if it fails, sound a repeating alarm tone and display a message like "System Fault - Disconnect Supply Immediately".  Ideally it would sense element current to determine if the iron is correctly connected and under control, but it would be possible to get a reasonable idea if there is a fault just from the bit temperature sensor behaviour quickly enough to sound the alarm well before the element overheats.

e.g. start by checking the bit is near ambient and there is no temperature rise with the element commanded off, then command a moderate duty cycle and check the temperature rises as expected, then close the control loop and check it can stabilise at lets say 50 deg C above ambient, before releasing it to normal operation.

[TheMG]

You were sold a defective product, why don't you contact the seller and get it exchanged for a new one?

I certainly wouldn't trust it anymore. If anything, the temperature sensing element could have been damaged meaning the temperature calibration could be way off. The heater's reliability would be affected too, it's not designed to ever get that hot.

[floobydust]

Chance it might not be a shorted MOSFET, if the thermocouple is wired backwards the controller will always think it is too cool and keep the heat on. Crappy sofware should never put full heat on for over a minute say. It could also be a wrongly wired wand if the cold-junction compensation thermistor is reading something wrong.

What temperature is it displaying? I would check the temps are not wrong.

[wraper]

Chance it might not be a shorted MOSFET, if the thermocouple is wired backwards the controller will always think it is too cool and keep the heat on. Crappy sofware should never put full heat on for over a minute say. It could also be a wrongly wired wand if the cold-junction compensation thermistor is reading something wrong.

What temperature is it displaying? I would check the temps are not wrong.

Maybe read opening post and some further info?

[ABSTA]

It was definitely a faulty Mosfet. I replaced it by an IRF9321PbF and it's fixed now.

This station is amazing


thank you for your support 

[wf789]

Hi I am having the same issue but the SMD cap @ C20 on the power board has blown for me... Would anyone happen to know the value? I can't find it anywhere online. The board ver is V2.01

Thanks

[floobydust]

Do you mean C20 on the 24VDC power supply? It's an 1uF across the output, not critical, put in anything 1-2.2uF.
Original is 25V running at 25V  so put in a 50V part for less smoke.