UNOLD Elegance Typ no. 58105 induction hotplate - Component identification

[mabinternet001]

Hi, I need help to identify the component with marking "9003 KAUCHB".

A bit of background...
I have an induction hotplate UNOLD Elegance Typ no. 58105 (with board CHK-A1.42S) which has a blown resistor.
I have also located the problem in the SOT23-6 component with the marking "9003 KAUCHB"; the pin 5 was disconnected from the IGBT emitter (ground) due to the high temperature and this caused the IGBT to be permanently ON.
I replaced the resistor and resoldered pin 5 of the SOT23-6 component to the IGBT, the hotplate worked for about a month and failed again due to the resistor (which I replaced with the correct resistance and wattage).
I now suspect that the SOT23-6 component marked "9003 KAUCHB" may be failing, due to the high temperature surrounding it, and I would like to replace it. Does anybody knows which component is it?
By the way, I think pins 2 and 5 are connected together; it is what I remember from the last time I repaired the board.

Thanks in advance

[CapLeaker]

You say the resistor goes open due to heat? Increase the wattage of the resistor or airflow. Would be my first ticket. Did you use silver solder?

[mabinternet001]

The component with marking “9003 KAUCHB” controls the IGBT “20N120”. In a normal operation, the IGBT only “pulses” to create the magnetic field in the main coil. If the IGBT fails and gets shorted, full power will flow throw the coil and it will burn the whole appliance. The now-blown resistor is in series to prevent this situation as it will cut the current flowing to the main coil when it burns itself (that is my understanding).

The component “9003 KAUCHB” is located in a bad place on the board, next to the IGBT, where a lot of heat is generated. There is a track under “9003 KAUCHB” from pin 5 (and I think also from pin 2) to ground (the emitter of the IGBT). This track is not visible on the photos, but got disconnected when the induction hotplate failed for the first time. The heat on the emitter was high enough to burn the thin and narrow copper trace going to the “9003 KAUCHB”.

When the “9003 KAUCHB” loses ground, the gate of the IGBT is always high. This situation is similar to a shorted IGBT when a permanent flow of current goes to the main coil. And this is when the now-blown resistor is relevant because it burns itself and cuts the flow of current.

I would like to replace the “9003 KAUCHB”, but I do not know what component it is. However, I have also thought in increasing the wattage of the 22 Ohm resistor from 3 to 5 Watts and see if the problem is solved.

[CapLeaker]

That's why it IS important to post a straight shot, high resolution picture from both sides of the board and not just snippets. What I do see is that this big inductor got hot and discoloured. May be worth checking. I think the power goes through the resistor into your induction coil to your IGBT. There should be a capacitor in parallel with that resistor and induction coil. So this should be a tuned tank circuit. If that capacitor changes in value, I would think it should sour your day and could cause the IGBT to blow again and again after a while.