i bought a used vivitar 3700 flash off ebay and it works, but the flash takes forever to refresh, sometimes 20 minutes or more, making it close to useless. one of the metal connector things in the battery compartment (the part that comes out, thankfully) is corroded pretty badly, i'm wondering if this is the reason the flash is running so slow? i'm willing to hunt down a new battery holder but i don't want to bother if this won't fix the problem.