***UPDATE***
Fixed! A reset using a paperclip on the magic little button seemed to do the trick!
***END OF UPDATE***
On my TT One 2nd Ed (Nav 7.162), I successfully purchased, downloaded, and installed the N. America maps for my new 2gb SD card, and everything works great . . .
. . . EXCEPT . . it will only turn if it's plugged in to external power (PC or car cigarette adapter), OR--if there's no external power--I have to take the SD card out and put it right back in again. In either of these two cases, it will start.
Once it's turned on using one of these two methods, it works fine. But obviously something's wrong with the booting up.
Thanks in advance for any tips.