I bought a Novatron flash unit with 3 heads, one of which had a broken tube. I bought a new tube on ebay, and replaced the old one...seems pretty hard to install it wrong; there were only 3 connections and I just soldered them where the old one went. However it doesn't work. The other 2 flash heads work. So either I got a bad tube, or the flash head internals were bad in addition to the flash tube being broken. I could take the new flash tube and try it on one of the other two working heads just to test it, but I was wondering if there is a break-in procedure you have to do to new flash tubes, or if it's possible that this new flash tube's breakdown voltage is higher than the other two, well-used flash tubes, and if so, if there's anything I can do to get it working.