Lost 'drive'

Don't.

The computer is telling you this? Does the nuvi work, and boot properly?

try updating the unit sw... via my dashboard.... see if that helps if not contact garmin.....

Nuvi boots okay but no map (white screen with default vehicle icon).

Tried updating, however doesn't "see" drive to update...

Tks

Do you have a complete back-up of your unit?

When I connect to PC, sees SD card, but not internal drive. Says the volume does not contain a valid file system. Looks like 'burnt toast' to me...

Yes, I have a backup, but no way to re-install...

Tells me I need to format the disk? What do I have to lose?

Careful now. You might need to format it, but lets make sure you have a full back-up. This means ALL the files the unit came with. Next, do you have lifetime Maps

Yes on both counts

Ok, lets go back to where you said it booted.
Do you get the main screen? That's with the "where to go" icon and the "view map icon"

yes

That's good news, in the sense that your nuvi is working. It does boot, and seems all works but the Map so at this stage there is no reason to format it. Do you remember what the last thing you did with it before it went hay-wire?

Had it connected to PC last night downloading last weeks tracks to MapSource. Left it connected to USB over night; when turned on this AM, above 'situation' noted.

Now I had something similar with my 765T. Lets hope yours doesn't have that problem. Do you have another usb cable we can try and if so shut the unit down and reboot your computer and then plug the unit into a different usb port. Lets see if it wants to format again.

Have to go pick up my wife; will check that out and get back to you later.

Many thanks for assistance...

Hope I can find my way. lol

Since you can get to your nuvi Main Menu but have no detailed map, have you checked your Map Info page to see if City Navigator is listed and that it's checked? That's what I suggest first. Tap Tools/Settings/Map/MapInfo and let us know what you see there. If this fixes things, you may be able to live for a while with a nuvi drive that the computer doesn't like, although I expect the issue will prevent WebUpdater or Map Update from working. I assume that now, you're also unable to use Mapsource (or POI Loader) to transfer anything to or from the nuvi. Reading that you have a completely white screen means to me that your nuvi is not using City Navigator and also is not even using the BaseMap, so the problem may be worse than just an unselected or corrupt City Nav.

I like Speed's idea of a computer reboot to see if anything clears. Another thing to do is a soft reset--rather than use the nuvi's power switch, remove the nuvi battery, then replace it, then see what happens. Since your nuvi does boot, you could also try a hard reset if you haven't tried that yet:

http://www.poi-factory.com/node/26136

Could the computer have gone to sleep/hibernation/ShutDown while files were still being transferred? Saying that you had to turn on the computer this morning means that it had shut down one way or another some time last night while the nuvi was still connected.

When doing any potentially long procedure, I make sure my PC is set to Always On, and at the end of my work, I do an "Eject" or "Safely Disconnect" of the nuvi and any SD card it has.

It's possible that your issue came from a shutdown in one way or another while work was still underway--sort of like just pulling the USB cord too early. A Safely Eject will let you know if you need to wait a while.

We may need Strephon's thoughts on things like MBR, formatting, etc. and it is possible that a format and restoration from a computer backup will work, but wait until there's a general consensus here that this is your best or only option since it'd be a last resort for me. I might even suggest a call to Garmin Tech Support to see if they have thoughts first, although I fear with all the new holiday nuvi gifts being opened soon that waiting time for Tech Support could be very long for the next couple of weeks.

Computer was not turned off, and 855 left connected (whick I usually do). MapInfo shows no map(s) installed.

Back later...

Hmm, if it wasn't turned off, then why did you say the issue arose when you turned on the computer this morning?

I wonder if the computer's Garmin USB driver could have gone bad. If others like the idea, one could try to uninstall, then reinstall them.

This might be a good time to tell us whether you're a Mac or PC person and what OS you're running and whether you see Garmin USB Drivers installed on your computer.

Don't think he was talking about turning the computer on, at least I don't read it that way. Sounds like he turned his nuvi on this morning.

Ah, could be. Then I'll go to my soft reset, hard reset, USB Drivers thoughts earlier, plus your "reboot the PC" and see what happens before thinking of a format.

This is, with all the knowledgable individual there is here. To take there time to help individuals that need help. Everyone deserves a COW.

Made for a good snack. Miss POI chuckled as she sent me the e-mail.

I checked with Garmin and they e-mail me a file.
Even though I could see the internal drive the file corrected the problem.

This would be much easier if his computer would recognize the drive. I don't think there's a thing wrong with the unit, just the maps are corrupted. But we need to get his computer to see the drive first. I'm thinking, his upload to mapsourse went wrong somehow and wiped his maps out. Rebooting i'm hoping will solve this issue. Wouldn't be the first time my units wouldn't list and i needed to reboot.

Computer was not turned off. When I disconnected the 855, turned it off, then back on.

Moot point now. The USB cable/port produced similiar results.

So bit the bullet - formatted the drive, copied the backup over, reflashed and reinstalled maps.

All okay now. Just haven't had a chance to check JCV, but I'm sure it should work okay.

Again, thanks to all for suggestions. I'll save for future reference.

Regards,

DougJ

That's funny..."bit the bullet" Glad it worked out.
You got real lucky. It booted, all was there but the maps, but computer couldn't read it other than it wants to format...always a scary thing. Doesn't make a lot of sense but. But as you said, last option nothing to loose.

Yeah, always nice when a plan comes together! lol

Also shows it's wise to have a recent full backup.

tks agn

We preach the back-up all the time in here, so many come here and don't pay attention, till its too late. I NEVER do an incremental back- up. That way I can just do what you did, and i do so once in a while...lol, cause I can't leave well enough alone. The restore process doesn't take much longer.

Well done...and it was what you figured you should do from the outset!

That's great to know that a format and restore from a backup works for our nuvis.

I checked with Garmin and they e-mail me a file.
Even though I could NOT see the internal drive the file corrected the problem.