Hi all, After about 15 weeks of no use (set theory course this term), my TI-89 is now completely unresponsive to any input. I have tried removing the batteries, holding down + + [2nd] + [on], and [-] + [)] while reinstalling one battery as indicated in the owner's manual. I have also tried the "blow hard into the USB port" solution. None of these have worked for me. My problem is essentially the same as those outlined here and here. Any advice would be very welcome! -- Ad Astra!