I recently acquired a ti-99/4a in somewhat decent condition for not much money, but I'm having an issue with it. On boot, it goes to the software select screen. I don't have a cart, so it only gives me the option to go into TI BASIC (as expected). The problem is, I get to BASIC for about a fraction of a second before the computer soft reboots on its own and then locks up upon the software select screen. Any ideas on where to look for the source of the problem?