KSGER T12 Soldering Station Repair - Shorted cable and popped MOSFET

My KSGER T12 Soldering Station developed a fault! I picked the iron up half way through soldering a project and it went bang! I opened the handle to find the red wire in the handle had disconnected from the solder lug and shorter on something else! From then on, all the screen showed was ERROR and B1 and the iron heated in an uncontrolled manner.
A quick Google found me the schematic, and reading how the device was supposed to work, I guessed the PMOS FET Q1 (TPC8107) had failed short circuit source to drain. This, the STM32F103 MCU was unable to read the temperature of the tip to know what to do.
Swapping out the TPC8107 fixed the issue, and soldering the red wire back and adding some better strain relief has my T12 iron working again!

[@KolyaNadj]

It is a useful video! I'm planning to order this station and think I'll order it as a kit and assemble it myself. You are not the only person pointing out that general production quality of this not great.

[@Skoolkidsproduction]

holy thank you, exact same problem. saved my night, found a P channel mosfet that matched on an old dell board i had lying around

[@cajuncoinhunter]

I don't have any issues with mine , but this is great information for future repairs.....

[@ddistrbd1]

I had to return my beloved Ksger 2.1S due to a malfunction, in my case when I tried to select a different tip , it would not show other selections I had programmed, instead the tip started to get cherry red hot like glowing red , this was the second (and the last) time it happened and as much as I loved this soldering station, I just could not have enough confidence in it any more and had to return it, but I did order a 3.1S version soon after and now I'm waiting for it to be delivered. these are in general great soldering stations .

[@Chaosek]

did that soreted your issue?

[@ddistrbd1]

@@Chaosek Yes it has been working without a problem, it's just a workhorse , as a hobbyist I doubt it will ever break on me again , no regrets at all.

[@nixontang8529]

had the exact same problem, thanks for sharing your finding. help me save my KSGER set

[@sergioswiszcz6015]

Thanks !! I had the same problem

[@carocalculon8781]

Do you also had problems in desoldering the pads on the circuit board?

[@gordonemery6949]

Thanks for the info just mended mine👍the black and the blue wires had both come off luckily fet was good 👍

[@m1geo]

Nice! My broken wires basically shorted the element and popped the FET. Glad got you it fixed!

[@gordonemery6949]

@@m1geo I was lucky ,I've taped the wires with kapton tape and hot glued around the cable relief ,to try help it out 👍

[@za_ozero]

I applied some liquid electric tape on connections to prevent wires moving in the handle

[@carocalculon8781]

Same problem here, but i tried to wick off the solder but the bridges stay or even get worse. Can anyone help?

[@carocalculon8781]

Now i checked the mosfet pins and found that there are 3 plus 4 on 1 contact and one single pin, so i am fine.

[@m1geo]

@@carocalculon8781 yes, as I me tho in the video, 4 pins on one side are all the same, and 3 pins on the other side. These parallel pins help with the current handling.