Thought my digital camera had come to an untimely end--"error 99" showed up each time I tried to take a picture. Internet search revealed much doom-and-gloom, ranging from people who had cleaned the lens contacts to those who'd shipped the camera off to Canon for minor fixes to disembowelment (not forgetting being without favourite camera for far-too-long).
So I read the manual.
Who knew. There is a separate "time/date" battery which is cleverly hidden inside the main battery compartment. And it has an active life of "about five years". About as long as I have had this dear camera.
It cost me about 5$ to replace... and five minutes finding the info in the manual.
For anyone else who wants to know what might be causing Error 99 without buying a new camera: Canon 30D user manual (copy)
EDIT--a few hours later. So much for that smug fix... it is failing again. Back to Error 99. It was worth a try... Can I go camera shopping now???
UPDATE: it cost $250 for Canon to fix it--it was the shutter assembly. Customer service told me what to do, how to ship, completed the data with me, and it was back home, safe, fixed and ready-to-go in under a week. They may have done themselves a dis-favour, as I didn't run out and buy a new one... but it's given me more time to save up for the Canon that I really want next!