Okay.
I'm not heartbroken, I got seven good years out of it.
Customer Support offered a while-they-last trade-in for a DriveSmart 55 with traffic, plus lifetime maps transferred from my old device, for $115. I might go with that. Is it a good deal? Or just start using my phone. I'm not driving around day in day out.
BTW I tried again with an 8GB Sandisk card and both capitalized and uncapitalized Update.txt name. No joy. It's dead Jim.
I could theoretically remove the flash chip with my hot air pencil but the outcome's uncertain and there are more rewarding things I'd rather be doing.
It was so good of you to help me troubleshoot this poor old thing.
-Dave