Hello everyone,

I have a Mi Air Purifier 3 for a year now and recently, it has been making this strange noise.

Any idea what it could be??

And does anyone have any recommendations on a general repairman or air purifier specialist who can get this fixed?

Thanks!

sound like one failing fan.
either the controller board failure or power supply shorting out. i dont think power supply are the one broken since the oled screen still show something and able to power up one fan, its a single voltage power supply anyway.

if the controller board that kaput (highly likely), its not going to be a cheap fix.

the board itself cost 55usd on aliexpress.
https://www.aliexpress.com/item/40007302534...c0ae8866fc9d-13

Is it possible that it's just a failing fan? Or it's almost guaranteed to be a controller board failure?

It is telling you it's time to get a new one

Ex Coway technician here. that sounds like something fell into the air vent. I never used a Xiaomi AP but I presume it's a cylinder type right? then something must have jam inside scratching the walls as it force to turn.

It's a common thing work any other AP products especially homes with kids. they like to insert all kinds of materials syilings, keys, matchsticks, mini toys all inside the air vent

I suggest you learn up how to dismantle the filters with YouTube see if you could find the stuff jam inside

This post has been edited by wktang: Jul 25 2021, 09:05 AM

1 year is too short for fans to fail, if the fan broke it is either the fan not moving at all or extreme vibration.

you need to dismantle the device first to see what is actually wrong in first place, the other forumer said something is stuck got some merit too.

need to open up and check, remove the filter from the back and look inside

Oof it's only 1 year old

Removed the filter and checked the fans. Nothing is stuck and it can be moved smoothly. It's on right now and there's no sound at all. But the noise will come back after approximately 15 minutes.

Also, are there any potential hazards like catching fire or some sort if I just leave it on?

Yes, things are not made to last forever.

Ngam ngam warranty finished, time to upgrade to newer version

I see. so may I know did the fan motor maintain speed level all the time or did you set it on auto mode? meaning when you start it up what is the speed of the fan motor? and did it change speed after 15 minutes?

I just checked my order history and it's actually 1 year 8 months old haha. Oh well.

When I start up it will go to the last previous speed that was set before turning off. It's at level 2 right now. No issues with the fan speed. At level 1, you can hear some light whining noise, but it's gone at level 2 and above. But the whining noise is completely different from the video I recorded.

This post has been edited by HalseyFrangipane: Jul 25 2021, 07:58 PM

means it's on level 1 right? most probably somewhere is out of assignment. this kind of problem is the trickiest to troubleshoot lol
You could mask the sound with higher speed level

Nope. It's on whichever level I turn it off with. I usually leave it at level 2. So when it's off and on again, it'll start with level 2.