Would a onetime snap and pop high voltage arc in a ten year old projection TV be more likely caused by dust and humidity or the aging of components?

Answer 1

This is likely to be caused by the ageing of components, specifically the plastics used for insulation. Dust and humidity will sometimes contribute to it, but not with new components. Some suggest that it is possible to seal the components with black silicon to prevent a repeat. However, the components that are affected carry up to 30000 volts. Not only do they operate at that voltage but they can retain that voltage for days or weeks after the television was last used. Don't under any circumstances try to repair a television unless you are properly trained and qualified to do so.