Houston.....we have a problem...

I got my flash out today, initially to simply get the batteries out and recharge them.  That simple act turned into a bit of a marathon as I discovered that there was a bigger issue than simply having flat batteries.  There seems to be a rattle in the head of the unit (kind of sounds like a tiny screw or something rattling around in there) and whilst power is clearly getting to the unit (the back screen is working fine) there's absolutely no power at all getting to the head.  A little google research told me that, unless I know what I'm doing, under no circumstances should I dive in there to find out what's going on.  I don't so I won't......which leaves a problem for me with B & R's wedding in a bit over a week!  Time to muster up a cavalry!!