Having a nice 38C with no battery I tried the AA alkaline with aluminum foil "trick" with the cells in the correct polarity position. Worked fine. Got too ambitious and tried the same with a pair of 1650mah NiMH batteries. Correct polarity again. They charged up nicely and ran the calc with no problems. For a while that is. After about an hour the display froze. Turned the calc off then on. Nothing. Even the double alkaline does not work. Have I fried some internal component? Simple thing like a resistor? Or have I baked something that can't be replaced.
Thanks