I am not sure if and how the controller checks the thermistor and thus you should check that one as well.
There are chances that the controller switches the heater off if the thermistor is gone.
As you are in a maker space I guess you have a multimeter at hand!?
with that you can check the continuity of the wires as well as the resistance of the heater sections and the thermistor.
You would need a needle for the wire checks in order to penetrate the insulation of the wires close to the heat bed.
With the multimeter in resistance mode and the the connectors disconnected from the controller first check if you can measure any resistance in the heat bed. Just from the connector. the heat bed (thicker white wires) should be in the low Ohms range and the thermistor should be around 100kOhms at room temperature.
In case one of the to is showing extreme high resistance this is the one were you have the pain to check if the wires are ok.
Here the needle gets handy. You stick it into the wire as close as possible to the heat bed and then measure that wire from the connector to the needle. if that is around 0 Ohms the wire is ok if not you probably found the culprit.
Repairing a broken wire is quick done if you have a soldering iron and some heat shrink at hand.
The Thermistor can be repaired / replaced as well. Here is only the calibration to be checked after replacing.
If the heat bed itself is burned… well… this to fix is not so easy… sorry
All the Best