Hi there, I think you pressed some more buttons and accidentaly you entered your device into Serial Mode (Bootloader), which you should update your ROM or reinstall your existing ROM in order to exit that state. I am sending you a link to HP website including your device's ROM upgrade download link, and a complete list of instructions. First of all, connect your device with a usb cable to your PC and see the "USB Mode" in the screen of your PDA. Also please be carefull and read the instructions very carefully before starting the process. Here is the link: (http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?swItem=ip-55697-1〈=en&cc=us&idx=0&mode=4&
Hope this helps. Have a nice day.