I caution that the testing discussed of this dynohub vs the other brand dyno hub is not detailed enough to draw a conclusion that your original hub is broken. Each dyno is designed to produce a set amount of voltage at a set RPM. At other RPMs, the voltage will vary quite a bit. And some are designed for primary use at lower RPMs, some for Higher. You should try to hold some variables constant and retest. As a start, I would recommend using/clamping a small motor to a nearby desk and running a belt or piece of surgical hose around the wheel. This will allow you to get control of the RPM variable. Then a meter will tell the story for that RPM. Could play with pulley size on the motor. The overall goal would be to get a enough values to plot a curve from a low RPM to a high RPM and then compare the two dynos...