im working in the phone and tablet repair bussines, so im using thermal camera alot.
I think its a very good tool for troubleshooting for shorts and abnormal behavior, but only if you are doing a lot of repairs, because a good thermal camera is expensive.
Im using a SEEK compact PRO and its the most popular model and brand in this bussnies.
A freezing spray could be used as well and are a much cheaper tool.