AAlthough your new angle grinder is really very simple to operate, if you do experience problems, please check the following:
1. If your grinder will not operate check the power at the main plug.
2. If your grinder wheel wobbles or vibrates, check that outer flange is tight, check that the wheel is correctly located on the flange plate.
3. If there is any evidence that the wheel is damaged do not use as the damaged wheel may disintegrate, remove it and replace with a new wheel. Dispose of old wheels sensibly.
4. If working on aluminum or a similar soft alloy, the wheel will soon become clogged and will not grind effectively.