If the power cuts out during the update, the projector may become permanently unusable.
Check the original listing where you purchased the device (GearBest, Banggood, or AliExpress). Most sellers provide a Google Drive or Mega.nz link upon request. unic uc40 projector software update download link
Carlos walked Elena through the process. If you own a Unic UC40, here is the safe, tested method: If the power cuts out during the update,