My made in Japan Vivitar 283 flash died on me recently. I used it back in late July shooting my friend's Rockabilly act (results in the main gallery) and it was working fine. Fast forward a few weeks later, I test it out before putting the flash in my camera and it's dead as in pining for the Fjords of Norway. Tried firing up with fresh batteries, nothing. So what's wrong? the contacts look ok, I might give them a quick clean and see if that helps but it is not an intermittent performance issue, the flash is plain DOA as in no power up whine, no flashing light on the back, nada. Thoughts?