TomTom 740 keeps getting lost

PaulB2005 · Posted: Mon Aug 03, 2009 3:03 pm Post subject: TomTom 740 keeps getting lost

This has happened a few times recently now.

Last weekend driving up the A1 my TT 740 suddenly goes grey and reports it lost signal xx seconds / minutes ago. This goes on for a few minutes until i can reset the device. Another 5 minutes up the A1 it happens again. And again. And again. The final time it happens i give up and it doesn't get signal back until I'm pulling up at my destination.

Last week the same happened again driving through town and started to show me about a mile from my actual location.

Again yesterday it was all over the place... A few roads over, random local locations and then somewhere i didn't recognise.

Today same again. Parked up waiting and it was jumping about. This afternoon on a journey and with 3 minutes to go more random jumping about.

Each time I've started the journey with a good lock before moving off. In the first instance (A1) i was using QuickGPSFix with NavCore 8.351. On the return journey the unit behaved just fine.

In the other instances i had NavCore 8.370 loaded and deleted the contents of the ephem folder. However it's generated some new files but only 2 instead of the normal 3.

The problem never seems to occur at the beginning of the journey but someway through.

Oh, and resetting the device seems to make no difference once it starts doing it..

Anyone else?

JohnMulholland · Posted: Mon Aug 03, 2009 3:52 pm Post subject: TomTom 740 keeps getting lost

Not exactly the same; but I have occasionally found my 740 telling me I've left the road and am now crossing a field. It happened in Kent in both directions on the same bit of road and in Cumbria; neither road was new or recently changed, as far as I know. It doesn't matter if it's a road you know or there are no impending junctions, but I dread it happening in a big city that I don't know.

John

jimbo_hippo · Frequent Visitor Joined: May 18, 2005 Posts: 444

Have you changed your car recently to one with an athermic windscreen or relocated it? If not then I would say it's broken and possibly a hardware fault. There are plenty of known issues at the moment but good GPS fix isn't you one you see much anymore as they all seem to get (and keep) sats very well.

I do A1 and M1 several times a month and my 720 never loses a signal (except in tunnels or under long bridges coming out of London which any GPS would).
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PaulB2005 · Posted: Mon Aug 03, 2009 4:38 pm Post subject:

jimbo_hippo · Frequent Visitor Joined: May 18, 2005 Posts: 444

Paul, I might be being a little hasty in saying it is hardware but if nothing has changed and its been reliable for ages it would lean that way. However, a clean re-install would prove me wrong and will be quicker than sending it away. Details of how to do this are on this forum.

Have you added any 3rd party applications? Software can do this but I've only ever had it on PDAs with telephone functionality back when I ran Navigator 6. Orange used to bundle stuff into their ROM which made the GPS drop in and out in exactly the way you describe but I've never had it/seen it on a Tom Tom supplied device.

However there are those on here who will no doubt leave me red faced. Those sad sad emoticons have got me all upset!
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Tom Tom GO 720
Orange M3100, Orange SPV M5000
TomTom Navigator 6, Destinator 6
Holux GPSslim

PaulB2005 · Posted: Mon Aug 03, 2009 5:28 pm Post subject:

Sorry didn't mean to upset anyone... Embarassed

I have no 3rd party apps so i'll see what happens this week.... Thanks again...

jimbo_hippo · Frequent Visitor Joined: May 18, 2005 Posts: 444

Good luck!
_________________
Tom Tom GO 720
Orange M3100, Orange SPV M5000
TomTom Navigator 6, Destinator 6
Holux GPSslim

falkirk81 · Posted: Mon Aug 03, 2009 5:40 pm Post subject:

It happens to me now and again. But usually corrects itself after a few minutes!
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Tomtom GO 1005 LIVE

iPhone 12

washman · Regular Visitor Joined: Mar 30, 2006 Posts: 75

Hi

It happens on my new XL IQ Routes as well.
Looses signal or shows you in middle of fields. The old XL worked OK on the same routes.

Mike
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TOMTOM XL IQ routes. UK & ROF I App 9.510.1234792.2 Map UK &RI V945.6174

jimbo_hippo · Frequent Visitor Joined: May 18, 2005 Posts: 444

OK chaps, looks like my advice might be based on lack of experience of newer units so maybe I'll duck out for a while and see if someone has better informed help.

Never get this on my 720. I have a list of things that drive me bananas but this isn't one o them! :-)

Jimbo
_________________
Tom Tom GO 720
Orange M3100, Orange SPV M5000
TomTom Navigator 6, Destinator 6
Holux GPSslim

stevea100 · Occasional Visitor Joined: Mar 31, 2008 Posts: 13

For what it is worth,,, when this occured on my one XL the fix was to delete the contents of the ephem folder. The unit worked better than ever and I now never use quick fix updates!

technik · Posted: Mon Aug 03, 2009 10:18 pm Post subject:

My 930 also used to lose satellite a lot with the latest firmware.

I solved the problem by loading an older last known good firmware, which also improves the route planning speed.

navver · Posted: Tue Aug 04, 2009 8:01 pm Post subject:

I had the same on my 520 on a very overcast wet day in town. I also have an athermic windscreen but this is normally absolutely fine.

I hadn't had the chance to update quickfix, when I did its been OK ever since.

If you have climate control you normally have an athermic windscreen a well. This was hopeless with my old Navman 635 but no trouble at all with my 520.

PaulB2005 · Posted: Tue Aug 04, 2009 8:05 pm Post subject:

No anthermic windscreen and the unit has been fine for 4 months until the last week. The car and position of the unit has not changed since it was bought.

Anyway today it got lost on 2 journeys with the ephem folder deleted and also got lost on 2 journeys with qGPS installed....

There has been another qGPS update tonight so i'll see what happens next and then it on to TomTom....

MrT · Posted: Wed Aug 05, 2009 8:10 am Post subject:

From what I can see there seems to be little point in deleting the GPS quick fix from the x40 range as they automatically update themselves over live services.

I have noticed recently that when a traffic download occurs with a very large number of incidents it can virtually stop the unit as it processes them, have you noticed that this loss of GPS occurs just before a number of incidents is displayed on the screen?
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