What electronic component is failing if an hour warm up is required for normal operation?

(My Original Blog Post: http://www.latesttrendsguide.com/?p=335)

I got a scanner, i know it got a very simple circuit board because i open it once, but it need warm up if i didn't use it for a month, if i use it yesterday, it won't require warm up to function as normal. So what is the component that need to replace, i suspect it would be the capacitor, if it is the case, would the big capacitor fail 1st or the small one. Any electronic repair expert kindly give me some ideas, thanks.

By: :D