CANON A640 Flash problem

I took it to a canon dealer who was going to charge me £70 just to diagnose the problem and then charge further for parts and labour. I decided to see if I can fix it myself. I've come accross the problem of the flash not working once or twice before when the batteries were getting flat. This problem was previously fixed when I used recharged batteries. The A640 uses AA batteries and I bought some rechargeable 2700mAh ones (give very good battery life). Recharged batteries didn't fix the problem this time though. I then decided to use a set of precision screw drivers which I'd bought from a £ shop and undid the screws on the bottom of the camera. I noticed that two of them were rather loose anyway. I then screwed them back in rather tightly. PROBLEM FIXED! My camera worked as it did before and the flash was working fine. It might have been a fluke but I have been screwing my camera into a tripod rather tightly hence the bottom of the camera may have come loose. Tightening the screws fixed the problem.

bulb is gone cost u 10$