920 went crazy yesterday and today, and some storage & reset Qs.

Joined
Dec 26, 2007
Messages
62
Location
North-Eastern NY
TomTom Model(s)
GO 920
Both days, about halfway into a 7 mile trip (still playing with the 920 and learning it's features, while using it around town), the unit goes crazy. It hiccups and places me on a road that I am not actually on. Some of the roads are almost an 1/8 of a mile distant. I get messages to make U-turns, and then I see the recalculating yellow-bar go across the screen 6 or 7 times within maybe 20 seconds. As I continue to drive, my car icon is either on a different road or between roads. Sometime it shows that I'm driving through a dense forest. The whole time, I have all 5 signal strength bars lit up.

When I arrived at home tonight, the signal was at full signal, and the unit was telling me that I was 2 blocks away from my actual position. I went to the "browse map" screen and hit the blue arrow in the top right corner to find myself on the map, and it too showed the incorrect location. I did an update of the satellites for the week a few days before the trouble, and the unit was fine for about 3 days, and then the trouble started, not right away. I've hit the reset button on the bottom and this makes no difference.

1) When I hit the reset button, the unit cycles off and stays off. Is this right? All my other electronic goodies turn back on after a reset.

I'll check it again tomorrow to see if it fixes itself.

I'm curious....I read that you can only have one backup on your PC. I backed up pretty much right after I removed the unit from the shipping box (as per this forum).

2) What is the recommended schedule to make backups...How often should it be done?

3) Should one wait a few days after updating the GO to make sure everything is working right before making a backup?

I'm considering hitting the restore/reset icon on the unit, but was wondering where all of my updates (POIs, map corrections, voices, schemes, etc.) are stored.
4) Are they only on the GO, or are they stored on the PC when you make a backup?

5) About a week ago I did hit the "copy to computer" icon in TTH. Did that save the POIs, corrections, voices and schemes to the computer (sorry don't remember)?

6) If I do hit the reset/restore icon, will it wipe out anything on my SD card?

7) What about corrections.... I've made corrections to both the built-in POIs and roads, and to POIs that I downloaded from this forum. Are all of these items saved during either a backup or during a "copy to computer"?

8) Is there any difference as to where the built-in map correction, and Map-Share corrections are stored?

9) Sometimes when I start the unit I get the drums, and other times it goes right to the startup image of my car that I loaded myself. Why is this?

Lots of questions...sorry :confused:
 
I'm not so sure that it is your unit going crazy as you describe in your first paragraph. That sounds like map inaccuracies to me. I see exactly the same thing in two areas near my home where it shows me driving on the wrong road or off the road quite a bit. sometimes it gives me similar directions as you describe.

I'd go back there again and see if it happens again. if it does, it's the map.

As for being home and the unit showing you two blocks from where you are....are you navigating to an address? If so, this is again the mapping. If however you're navigating to a previously marked "home" that you input manually while at your home, it would be the unit.

1. yes, the unit stays off on a reset.

2. once in a while should be fine, and certainly after every time you add something to the unit. You can backup as many times as you like and have as many backups as you want on your computer if you use a file manager to copy all the files to a different folder on your computer each time. The home program does a backup to one specific spot and will overwrite or modify that backup each time you do it again. a file manager backup is easier and faster.

3. your choice. remember, you can make as many backups as you want.

4. stored on the go, and when you make a backup stored there as well.

5. yes, in the default home backup folder...my computer/user/tomtom/backup ....that's not quite the exact path, but close.

6. If you mean the reset the system to default icon...no.

7. yes

8. can't tell you that, but I assume it's inside the map folder on the unit somewhere...these would also be copied to the computer on any backup.

9. not sure why this is, but I sometimes see this myself, usually after I've taken the sd card out of the unit. nothing to worry about.

you're welcome....:)
 
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My 720 started doing the same thing tonight......showed me at home location, except it placed me on a road parallel to mine and a 1/2 mile away --- on the other side of railroad tracks!!

The only thing I had done was insert a basically empty 4 gig sd card in the unit -- no maps or anything on it.

I even took the unit into my car and the mapping went crazy as I went for a drive around my local streets. The 720 couldn't figure out where I was. Yes, I had signals from 6 satellites.

Resetting did no good. Neither did downloading and running the Clear Flash tool.

Finally, docking the unit and running TTHome (2.221) and invoking the Virtual Go placed me back on my proper street.

I have no explanation ... but it's unnerving, to say the least.
 
Thank you flyer1024 & dhn........

It's definitely not map error. This is a route I've been taking since I got the TT. yesterday and today were the only days I've experienced this.

I'm thinking it was something weird going on with the satellites, hard as it seems to believe.

Forgot to mention it before.... Yesterday, while driving home, it did something else weird that I had not seen before. Let me set this up....imagine looking at the face of a clock, with your car at the pivot point of where the hands would typically be. While driving down a straight road, your path runs from let's say 6:00 (behind you) to 12:00 (straight ahead of you). Well yesterday while driving down this straight road I've taken plenty of times in the past, all of a sudden the road (on the TT) turned and ran fron 7:00 to 1:00. then it switched again, this time to 5:00 to 11:00. It did this quite rapidly a number of times. Instead of one road running straight ahead on the display, I had what looked like the letter X on the screen as the road rapidly changed between these two points on a clock. After that, it starting recalculating over and over, in rapid succession. It knew I was making turns, and was trying to put me on a road that was also making turns, but it was not the correct road. I kept getting the "make a U-turn" dialog. The only thing that could make it right was to turn the TT off and then back on. All the time while it was screwing up, the car icon stayed centered at the bottom of the screen (off road) pointing straight up toward 12:00.
 
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I started to get the same thing on my 720. I wonder if it has anything to do with the SD card.

I don't know.....

This morning, my unit started acting up again. I wasn't being placed on a different street this time but the icon showed me not in the proper place.

Also, the unit is losing the setting for the car icon I selected.

So, I ran the Clear Flash again with the (almost blank) sd card in the unit and, for the moment, I'm back to where I want to be.

And again, I find running the Virtual Go on the TTHome software places me properly.

Obviously, I'll keep monitoring the situation.
 
I have been having problems the last couple of days also with this same thing on my 920. Only I am not as far off as some have posted.

I am running App 7.221 (8572/071121) OS:2318
GPS v1.21, Boot 5.4106
Map NA v710.1576

This is a new problem that cropped up on Thursday evening, as I closed in on Palm Springs. I updated on Wed night. It had been working fine earlier in the day, and I did not update anything again until today.
 
This is a new problem that cropped up on Thursday evening, as I closed in on Palm Springs. I updated on Wed night. It had been working fine earlier in the day, and I did not update anything again until today.

Is it still happening after today's update?
 
DHN,

Try a recalibration.

Go to the screen with the GPS satellites and strength bars and tap configure. Choose the 3rd option, the one at the bottom and tap done.

This needs to be done in the open, away from trees and buildings.
 
I have been having problems the last couple of days also with this same thing on my 920. Only I am not as far off as some have posted.

I am running App 7.221 (8572/071121) OS:2318
GPS v1.21, Boot 5.4106
Map NA v710.1576

This is a new problem that cropped up on Thursday evening, as I closed in on Palm Springs. I updated on Wed night. It had been working fine earlier in the day, and I did not update anything again until today.

96ss...On my 920 I am running 7.220. Is 7.221 on your 920T or your 700.

And are the App updates the ones you get when you connect to TTH and the software automatically looks for updates? Or do you get them elsewhere? Not quite sure.
 
This seems to be recently affecting all kinds of units...920s, 720s and 910s...must thus be related to the QuickGPSfix download in the past week.

910s never had this problem before...that is the key.
 
dhn.....Are you talking about the GPS Quickfix, that updates the satellite positions? Or are you talking about something else?


Sorry......was referring to the quickfix download of yesterday.

At the moment, the location for Home is back to normal (which means 8 houses away from the true location :eek: ) for me.

So, indeed, the quickfix of a few days ago may have been incorrect, especially as has been pointed out, all types of models are having the problem of 'drift'.
 
Why do we even need the Quickfix updates? I have a 8 year old Magellan Sporttrak Pro, handheld GPS. It never needed any satellite fixes. I just turned it on and within maybe 20 to 30 seconds, it had acquired at least 3 satellites and the WAAS. Yes, there was no way to plug it in and update it, as that was not something available at the time.

What would happen if we chose not to accept the Quickfix? I thought that I read it was something to help the unit 'know" where the satellites were going to be for the next week, and to help it speed up the unit's boot time. Aren't they geosynchronous, and pretty much stay in the same location relative to the rotating earth?
 
GPS satts are not geosynch as far as I know, otherwise they wouldn't cover the entire globe.

You dont have to take the Fix. It is there to help establish a faster time to first fix and normally works GREAT, making the TTS the fastest to get signal. Ephemeris data takes at lest 30secs to download, so that is a constarint without the FIX. With the fix, you have pseudo-ephemeris data and can start working faster.

Remember, many PNDs are beneath athermic windshields and so have attenuated signal. The Fix helps there too.
 
96ss...On my 920 I am running 7.220. Is 7.221 on your 920T or your 700.

And are the App updates the ones you get when you connect to TTH and the software automatically looks for updates? Or do you get them elsewhere? Not quite sure.


That is what I am running on my 920T. That is what I got from TTH.
 
That is what I am running on my 920T. That is what I got from TTH.


I have been connecting my 920 to my PC and running TTH pretty much every day since I got it. Why haven't I gotten the 7.221 update? I thought that when I connect, and I select the TT not the SD card, it should give me any available updates. Is there something else I must do?

Infama....when I go to the GPS satellite screen the only option I see is whether I want Degrees, or degrees and seconds and a third choice(or something similar...don't have the unit in front of me at the moment). Am I at the wrong screen?

FYI...my unit has been working fine as of late. it was just those 2 days in arow where it was acting strange.
 
I have been connecting my 920 to my PC and running TTH pretty much every day since I got it. Why haven't I gotten the 7.221 update? I thought that when I connect, and I select the TT not the SD card, it should give me any available updates. Is there something else I must do?

Infama....when I go to the GPS satellite screen the only option I see is whether I want Degrees, or degrees and seconds and a third choice(or something similar...don't have the unit in front of me at the moment). Am I at the wrong screen?

FYI...my unit has been working fine as of late. it was just those 2 days in arow where it was acting strange.

You are on the right screen. Choose the third (bottom) option while in a wide open area outdoors. This apparently recalibrates the device.
 

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