A Preethi mixer grinder that suddenly stops working is frustrating, but the cause is usually simple and often fixable at home. Before you call service, this guide walks through the most common reasons a Preethi mixer will not run — and exactly how to fix each one.
Quick Answer
If your Preethi mixer grinder is not working, the most common causes are a tripped overload protector, worn carbon brushes, a loose or worn coupler, or a power/switch fault. Start by pressing the overload reset button under the base, check the power and socket, and inspect the coupler. Most issues are resolved without a technician.
Common Causes
- Overload protector tripped: Heavy grinding overheats the motor and the safety cut-off stops it.
- Worn carbon brushes: Over years of use the brushes wear down and the motor stops getting power.
- Loose or worn coupler: The rubber coupler that drives the jar can wear out, so the motor spins but the blade does not.
- Power or socket fault: A loose plug, tripped MCB or faulty socket can cut power.
- Faulty switch or jar safety lock: If the jar is not seated correctly, the safety lock prevents the motor from starting.
Step-by-Step Fixes
1. Press the overload reset button
Unplug the mixer and let it cool for 15–20 minutes. Turn the unit over and press the small reset button on the base. Plug back in and try again. This fixes most sudden stoppages after heavy grinding. If it keeps tripping, read our guide on why a mixer grinder overheats and stops.
2. Check power and socket
Plug another appliance into the same socket to confirm it works. Check the MCB and that the plug is firm. A loose connection is an easy thing to overlook.
3. Reseat the jar
Remove and refit the jar, locking it firmly into position. Preethi mixers have a safety mechanism that will not let the motor start unless the jar is seated correctly.
4. Inspect the coupler
If the motor hums or spins but the blade does not turn, the rubber coupler is likely worn or cracked. It is a cheap Preethi spare and easy to replace at home.
5. Check the carbon brushes
If the mixer is several years old and suddenly stops, worn carbon brushes are a likely cause. These are a standard wear part — see our guide on how to replace a mixer grinder brush at home.
How to Prevent It Happening Again
- Grind in short bursts of 2–4 minutes with cooling breaks during heavy sessions.
- Do not overfill jars past the marked line.
- Replace worn brushes, couplers and gaskets promptly.
- Keep the jar base and coupler dry to prevent rust and slipping.
- Clean jars regularly so residue does not strain the blades — see our jar cleaning guide.
When to Call a Technician
Call authorised Preethi service if:
- The motor hums but will not turn even after checking the coupler and overload reset.
- You smell burning or see smoke — see our guide on the mixer grinder burning smell.
- There is sparking from the motor area or the switch is damaged.
- The mixer is under warranty — opening it yourself may void the cover.
Frequently Asked Questions
Where is the reset button on a Preethi mixer grinder?
It is a small button on the underside of the base. Press it after the motor has cooled to reset the overload protector.
Why does my Preethi motor hum but not spin?
This usually means a worn coupler or, less often, a seized motor or capacitor fault. Check the coupler first, as it is the cheapest and most common cause.
How often do Preethi carbon brushes need replacing?
Depending on use, every 3 to 5 years. If a several-year-old mixer suddenly stops, worn brushes are a likely cause.
Is it safe to repair a Preethi mixer at home?
Simple tasks like resetting the overload, reseating the jar or replacing the coupler are safe. For motor, wiring or burning issues, use authorised service.
Most Preethi mixer grinder problems come down to the overload protector, brushes, coupler or power supply — all easy to check. Work through these steps before calling service, and you will often have your mixer running again in minutes.