Thank you Doug for making this community possible! This thread alone saved at least several times the amount of my annual donation. (And I'd rather see you get the $ than Garmin, anyway.

)
Since last spring, life happened, and I went close to a year without using my 296. I powered it up a couple of weeks ago and it wouldn't acquire satellites, even after leaving it on for 5 minutes the satellite status page showed flatline on all channels. It had NEVER taken anywhere close to that long to find itself. I checked the manual, and the word "troubleshoot" does not appear ANYWHERE in it.
Before giving in and having Garmin look at it, I decided to search the VAF forums, and found this thread, among others. Before reading this, I had not even noticed that the clock was off. I left the unit on for 15 minutes and voila, it eventually started tracking satellites.
The next problem occurred almost immediately when I turned off the unit to let the main battery charge, and got a "Battery Missing" message. The unit would not power on unless connected to an external source. The main battery was obviously not "missing", so I reread this thread and noticed that that message refers to the clock battery, not the main battery... something that Garmin support folks don't even seem to know.
I also learned that the clock battery is rechargable (the unit has to be ON; that's why it died after months of disuse), so I didn't need to immediately go tearing into the unit to replace it. (There's also a thread here detailing how that is done, should it ever become necessary

). Sometime during the second hour of ON time the unit finally decided that the battery wasn't missing after all, and life is now good. Now, by the time I get through the legalese screen, the unit is tracking a 3D solution.
Garmin Service: $350 saved. New main battery: $60 saved. VAF forums: PRICELESS!