Once the tip get that hot it probably is kaput. The heater may still work, but there is no guarantee of sensible temperature measurement.
The original fault may have been in a faulty temperature feedback, such as a shorted resistor on the PCB, so also check for that.
In the beginning of 3D printers, a common fault was that a lot of stringy plastic pulled out the temperature sensor of the "hot end", which caused the "hot end" to be full on, overheat and cause fires. Then somebody got smart and added a check if the power input to the heater resulted in reasonable temperature change feedback from the thermometer, and if the feedback does not make sense, it just shuts everything off and goes into alarm mode.
Does the TS100 have firmware that does this?