Mine went beserk a couple of years back. I opened it up and gave it a clean, and it worked fine, if only for around 10 months. Then it completely packed in so I got a new slim one. Suddenly about a month after I had it, it stopped working. I phoned up the Careline and they said they would give me a new one for free because it was new. I have that one now, and there are no problems.

In short, shell out on the new one.