The fault description sounds like the RL2 is not working properly, it’s likely to be stuck to closed position which short circuits the R7. This can be verified by listening to relay clicks when the Argon STO is turned off.
Argon requires STO signal to turn on the safety relay RL1 that connects HV voltage to the capacitors. After the HV voltage has stabilized the RL2 is turned on to short the inrush current limit resistor R7.
Should this be the case, you can try to open the RL2 by SHORTLY connecting 5 to 9 volts shortly to the relay coil pins few times. The coil pins are the closer ones to each other, picture below, A1 and A2 pins.
If that doesn’t help, it’s possible to open the relay packet and mechanically open the connection. Or replace the relay altogether.
That broken transistor is indeed IGBT and STGF14NC60KD would be better replacement for the original part. It is the driver for the braking resistor. I find it weird that it has broken, might have been a voltage spike in the HV bus because the bypass relay hasn’t worked ok. Cannot say with 100% certainty though.
Let us know how the repairs go.
Kind regards, Esa