About the fault, when the unit is old and accumulates metal particles on the filter, it will start arching. The electrostatic discharge is often damaging the internal on-board components, the parts must be tested at component level.
About the unit, as personal opinion, I think that the high quantity of ozone produced by the units you have at home is dangerous for your health, and ozone generators are bad for your health.
This was sanctioned in court, along with an order to retire from commerce the Alpine air ozone generators. The original verdict was reverted in appeal, I guess consumer association had no more money to pay legal expenses. Here the story as reported from Alpine Home Air:
Alpine Air Purifiers - Ozone Generator.In court it was demonstrated that quantities that are over safety level, can help in determined illnesses, therefore Ozone machines cannot be banned, as they are needed for medical patologies. In this contest quantity of ozone that are far over safety standards are needed.
According to EPA, and to health and safety standard worldwide, National Ambient Air Quality Standard for ozone is a maximum 8 hour average
outdoor concentration of 0.08
ppm.This unit works indoor, and it is capable of producing far more ozone than safety standards.
This is no medical advice, I am an engineer, not a doctor. As said I think that this machines should be used only if you have a patology that may benefit from inalating Ozone. I would not put this kind of air purifier in a healty kid's room for example.
Here a survey from Canadian govermental authority reporting quantity of Ozone produced by this model:
converting...Ozone Purifier Survey.