Recently purchased a new HP 17bII+ financial calculator to replace my previous HP financial calculator that I used for 12 years. I am very familiar with this model, albeit an earlier generation. Frequently when I enter a number for a calculation the display remains blank. I have to press the keys a number of times in order to activate the device. I know that it is not a key problem, because it happens whenever the unit is idle for a period of time. Once it has been activated, it works flawlessly.