Repair of Levoit LV-PUR131 air purifier.

Today I repaired my Levoit LV-PUR131 air purifier. It showed a lit red on/off button but none of the controls responded to touch. I used the information at the Youtube video. Apparently this is a common problem that has been occurring for years.

Levoit Air Purifier Power Supply Repair

Like in the video the power supply was not working, two 16v 470uf electrolytic capacitors were bad. While they did not leak they were bulging on top. I noted another problem, the power transistor (or mosfet - I couldn't read the part number) beside the two caps was touching a plug on the corner and the plug was discoloured at the contact point. It appeared to be extremely hot at some point. I don't know if the failure of the caps caused the transistor to be very hot, the heat caused the failure of the caps or if that component just runs very hot. Either way I added a small aluminum heat sink to the component making sure there was nothing around that could short out.

I replaced the 16v 470uf caps with 35v 470uf caps. I used a small 60watt soldering iron and a solder sucker. The solder sucker works well to remove solder and makes the job much easier. I find a solder sucker works better than desoldering wick which requires a lot more heat.

The air purifier works again.