I just bought a refurbished s10-3t to replace my old Y430 (refuses to charge anymore. Fought with it for a week before I decided it was time for a new computer.) and now I'm having issues. I haven't even had the netbook for a day.
Once I go it, I turned it on to make sure everything was working properly. Although, it was a little slow, I was satisfied. So, I shut it down and upgraded the RAM. When I turned it on again, the screen refused to turn on. I don't know what I did. I tried unplugging it, the rebooting button, taking the hard drive out... Non of this did anything. It's making noise and running as if it were perfectly fine, but the screen won't start. I tried hooking it up to a monitor, and that didn't show up either.
Be sure the memory is seated properly. If that is no help put the old back in to be sure your memory is okay. If no joy, then unplug the unit, take out the battery and press and hold the power button for ten seconds. If there is a reset on the bottom press it.
If that doesn't help then I'd contact the people you bought it from.