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A short note on fixing a wet grinder. Before we start a brief history on wet grinders. You can say wet grinders started the industrialization of Coimbatore. Read about it here. https://www.google.com/amp/s/www.thehindu.com/books/historian-cr-elangovans-new-book-documents-the-citys-connection-with-the-invention-of-the-electric-wet-grinders/article22122892.ece/amp/
A wet grinder is s deceptively simple machine. The ingenuity lies in the timeless design. There are three major internal parts - the motor, a capacitor and a belt such rotates a flywheel/pulley kinda thing. Like this 
https://images.app.goo.gl/mwdKHeUU6BjKBq3W8
https://images.app.goo.gl/mwdKHeUU6BjKBq3W8
The capacitor helps in starting up the motor. If your grinder won't start, simply replace the capacitor, with an equivalent model. The same applies to kitchen chimneys, ceiling fans etc. It's a straightforward task. You might not even need soldering skills.
In my home, my wife and maid were complaining about low power output and grinder getting stuck when you add rice. Initially I suspected a faulty motor. I was planning to get the windings redone. But a quick check in the rpm, measured crudely, with my eyes confirmed that (+)
the motor was good. So the culprit was the belt, which wasn't transferring the power/torque to the pulley. On closer look, the teeth in the belt had worn out. I got a similar belt from a shop in Mannurpettai. There is a code on the belt, which you can use to get a new one.
Check out the difference in the picture below. Unfortunately, this was the only pic I clicked. After, the belt was replaced, I had to reconnect the ground wire, which had worn off. And voila, the grinder just made mincemeat of the rice 
So before scrapping/calling the service center, open up and see if you can fix the problem. Please do take adequate precautions when dealing with electrical appliances. I have used many terms liberally, for ease of understanding. Happy #DIY 