Flash problem- making me VERY cranky

[Outdoorsman]

I've been using my old 420 EZ flash with my new Elan 7N, and so far it's been just fine. But recently I shot my nephew's birthday party. The flash did not fire for a single shot; a good hour's worth of following little kids around with a big attachment on the camera for what apparently was no reason. I was just a little conspicuous, you might say. The conditions were 3:00 in the afternoon in direct sunlight. Of course the shots were contrasty but still OK. I wanted some fill to balance out the harsh shadows, but no dice. The worst was when they moved into the shade to have him blow out the candles. Most of the shot was in the shade, with only a little part in direct sunlight. And the flish still did not go off. Of course with one eye closed and the other in the viewfinder, I did not see if the flash fired then, but now I'm stuck with a very dark shot of the kid blowing out his candles and one little part of the frame correctly exposed. (see photo) It's as if the camera ignored all but the brightest part of the frame and didn't bother to take into account the fact that the flash was on. I have my younger brother's 8th grade graduation to shoot next week, and I'd hate to think my flash has croaked with no time to replace it- using the built-in flash will be a nightmare... any ideas?