B+ is the DC power supply for the chassis. There will be a place to test it pretty much on every chassis. Some are adjustable, some auto adjust. If it's no where close to what it's supposed to be then you have a problem.Thanks for the comment man! im little versed in this topic, what do you mean by b+?
You mentioned you have a wei ya so you could search your chassis model and b+ test point to find more info.