1)Make sure the calc is On, and at the Home screen of the TIOS. If the calc isnt responding, Take out any one of the 4 AAA batteries, count to 3, and then put it back in. press On, and see if the calculator is working now.
2)Check the contrast. if the contrast is too high/low, use 2nd + up/down keys to adjust.
3)Make sure you have fresh batteries in the calc.
4)Go to Cemetech.net and see if some more professional help can diagnose the problem. most of the time it is something above, but it has been known that the calc breaks due to battery acids, liquids, or heavy jostling.
