Wt is the reason for laptop produce buit rning smell when start?

Something in the laptop has either been shorted out or failed.

you should never smell burning from a laptop.

send it back and get it repaired under warranty.

remove power cord and battery, and don't keep trying to turn it on until it's fixed because you might cause more damage.

You should follow these below points…

1. Troubleshoot the laptop by shutting down the computer and removing the AC adapter and the battery. Some laptop batteries can't be removed unless the casing plate is unscrewed from the base.

2. Attach the AC adapter to the computer and turn the computer back on. If there's no smoking smell and laptop does not get hot, then the battery is faulty and must be replaced.

3. Continue to troubleshoot the laptop by moving it to a hard surface such a lap desk or a table. On some laptops, the vents will not function properly when the laptop is on a cloth surface. The overheating caused by the soft surface blocking the vents may cause a burning smell. Manufacturers of computers recommend keeping the laptop on a hard surface for proper airflow to cool the laptop.

4. Clean the laptop by lifting up the keyboard from the case. Check your laptop's user manual for guidelines on cleaning. Use a small hand vacuum to clean any dust.

5
Check that fan is running by listening for the sound of a fan while the computer is on. Even quiet laptops emit a low whirring noise. If the smell continues and there's no whirring noise from the fan, shut the laptop down immediately and have the fan replaced.

Buy Dust-Off Compressed Gas Duster and clean your fan.

http://allbestlaptop.com/clean-laptop-fan-without-opening/