I just had to share this story. I picked up a 48SX with a broken display as a door prize at HHC2011. Not surprisingly, when I put batteries in and tried it, nothing happened.
Today I tried again, figuring that I'd try to induce a computation error and see if it would beep. Again, no luck.
I tried adjusting the contrast. Nothing.
I tried pressing the ON button harder, and many times. Suddenly it turned on!!! The display has some marks on it, but it's perfectly readable.
Then I tried to turn it off.... it wouldn't go off. Hmmmmmm.......
Then I remembered reading here that keyboard failure is common on some models and if you press under the display, it causes two contacts to come together that fix the problem. I pressed under the display, and I was able to turn it off and on at will.
So the bottom line is that the display has a few nasty marks but is otherwise okay. The real problem is just that the ON key doesn't register. That's alright, I just want to play around with the machine anyway.
Dave