Tiablo ACE-G "flickering"

Hi,

I got a Tiablo ACE-G from IS’ recent garage sale, and it arrived today. It’s built like a tank :)!

Anyway, I put an 18650 battery in it, and when I press momentary, it comes on fairly bright. However, if I click all the way through, the light stays on, but it’s dim, and flickering.

I’ve tried several different batteries, all charged recently, but it behaves the same with all of them.

Has anyone had one of these, or had this happen? What is causing it, and what can I do to get it working better, since the stuff bought off of the garage sale were “as-is”?

BTW, this light appears to have an MC-E emitter and only one mode? Is that right?

Thanks,
Jim