Detecting a motherboard short circuit using a rosin dispenser can be a somewhat technical task. Here's a general approach:
First, power off the computer and disconnect it from any power source. Then, carefully remove the motherboard from the computer case.
Next, heat up the rosin dispenser to an appropriate temperature. Once heated, apply a thin and even layer of rosin to the components and traces on the motherboard.
If there is a short circuit, the heat generated at the shorted point will cause the rosin to melt and bubble more prominently in that area. This visual indication can help you identify the potential location of the short circuit.
It's important to note that this method requires some experience and caution. You need to be careful not to apply too much heat or rosin, as it could potentially cause further damage to the motherboard.
Also, keep in mind that this is a basic technique and might not always accurately detect complex or hidden short circuits. In some cases, using specialized testing equipment or seeking professional assistance might be a better option.
Hope this gives you a general idea of how to approach detecting motherboard short circuits with a rosin dispenser.