There is absolutely no need to throw away broken power tools these days, thanks to the availability of repair manuals and power tool spare parts on the internet. Power tools only usually die due to a broken switch, broken power cord, worn out brushes and snapped drive belts.
Power tools with powerful motors usually suffer eventually from a broken power switch, which is very easy to repair. Body grinders and circular saws are particularly prone to broken switches. Again, an online search should reveal the part number of the switch, which can be purchased online at a very cheap price. To replace it, remove the wires from the switch and push the switch out. Then, it is just a case of pushing in the new one and attaching the wires.
Power cord issues are more difficult to diagnose. The best way to discover wear broken wires are located in the cord is to push needles into the cord and monitor using electricity meter clips. A new piece of cord can easily be purchased online and attached to the old cord before the break. An old computer power cord can also be used as a replacement cord.
Body Grinders, routers, and other tools that run at high loads for long periods of time wear out their brushes quickest. Fortunately, it is possible to check up on the brushes condition by removing a plastic cover on the power tool that is held in place with a bolt. It is worth purchasing some replacement brushes from a reputable online store that sells power tool spare parts, so that they can be replaced before they completely wear out. Replacing the brushes is very easy with the help of an online repair manual specific to the power tool model.
Power tools that use a drive belt, such as belt-sanders, planers and rug-beater style vacuum cleaners usually die because the belt has snapped due to wear. Entering the model of the power tool along with the words-replacement drive belt into a search engine, will give you the part number for your specific belt. You can then order a new one at a chap price from a good online retailer. With the help of an online manual for your specific power tool, you should be able to replace the drive belt with ease.