If the LED works but the UV tube fails to light, it most likely indicates that
the tube may have moved in transit and will require re-seating into the
terminals at each end of the unit.
On-Off switch to the middle 'off' position.
Pull-off the 'Snap-Fit' plastic cover and gently rotate the UV tube one
quarter-turn. Switch-on the UV tube. If it still does not illuminate,
repeat the above process until it does.
When the UV Tube illuminates, it will do so initially at half power for
approximately 1 second, then brighten to full power.
If it does not brighten, it means the batteries are now too weak to be
fully effective and require