Quoted from pintechev:1) Don't fix things that aren't broken; you often make things worse...
+1
My first idea is usually wrong. So I don't try fixing something immediately after noticing it isn't working. I like to think on it for a few days... Look through the manual... Read some Pinside... Think some more. Ideally I like come up with a logical explanation for why the thing stopped working before I dig in.