My navigation unit is about 9 months old. This summer, it got left in the window on a hot day while I was at work. (I was in a hurry and forgot to remove when I parked my car.) Since that day, my C340 will no longer power on unless it is connected to a power source. It seems the internal battery does not/will not hold a charge. Has anyone else had a problem like this before? How was it solved (if it can be solved)? I contacted Garmin and they told me to hold the power button and press on the lower right corner of the screen, that was supposed to reset the unit. I don’t know if it reset my Garmin, but I do know that it still will not hold any type of a charge. My C340, does work still, although it seems to take longer to aquire satellites than it did before, but the directions are still right on the money. If anyone has any suggestions for me I would appreciate.