Hi Simon,
Yes, you may be in a "un" fix. Yet, before you open it up, try removing the batteries, and soaking in distilled water for a day, and then thoroughly dry it in natural air, with a fan if you like, for about 3 days. Sometimes, the pad that puts pressure on the connectors becomes compressed, and the moisture sems to re-liven it (it is made from foam).
Generally, with this sort of problem, you also see the ability to make the operators work again by simply putting gentle but firm pressure to the bezel just below the display. If this is the case with you, then do not fret--just try this first.
I also suggest that you be patient with purchasing a back-up 32sii--I have never paid more than $ 130 for one--and the last one I bought 3 months ago, I got for under $100.
You might also go get a 33s. I know, it isn't as nice--except that you never run out of memory ever--and the equation list is better--the unary minus is no longer precedent. There are some bugs--which have been thoroughly analyzed here---but they can be worked around (worst is the sexagesimal, and the polar conversion bugs--and the RAD annunciator bug after reset). It is only $43 if you buy from Amazon and get the $10 rebate.
Best regards,
Bill