Uv flashlight problem

[jonnyques]

Recently my hand held uv flashlight has started to strobe. Just wondering if anyone also has experience this? Anyone found a fix? I've tried different batteries, and verified contacts are all clean.
Thanks

[screenman]

Take the end off and you will see a ring with two holes in, is this tight? How many of us drop the light into our boxes and chuck the boxes about, I am sure I am not the only one.