TT BT GPS unhappy in warm weather?

NMatthew

In the last couple of weeks I have had an irritating problem with my TomTom Bluetooth GPS receiver. Sometimes it just won't turn on.

The usual startup sequence is: press and hold button for two seconds or more. Normally I get a blue LED flash, the grene LED turns on for a second or two and then goes off. Thereafter the blue LED flashes awaiting a PDA connection and after a little longer the green LED flashes indicating it knows my location.

Sometimes however, the startup sequence fails. There may or may not be a single flash from the blue LED, but the green LED will not do its stuff and I end up with LEDs at all. This condition can persist for a long time. I can go through the usual shutdown sequence (press and hold the button for five seconds or more) and try again, all to no avail.

The device is not completely broken since it will eventually come back and a normal startup sequence will succeed.

I am beginning to think that the problem is heat related. I have the GPS in a car cradle in the windcsreen of the car. I get a good startup in the morning, but have recently been getting this poor behaviour when leaving the office, having left the GPS in situ. If I stop on the way home after about 20 minutes with the air-conditioing running, the GPS will fire up OK. The problem started as the weather began to improve and we saw some sunshine.

Has anyone else seen this behaviour?

I would have thought that the device would be engineered to tolerate in-car temperatures as it is designed to operate with a clear view of the sky - hence in direct sunlight. It rather defeats the option of wiring-in if you have to take the GPS out of the cradle, and carry it with you every day to avoid it getting too warm!

Neil

davisr_uk · Occasional Visitor Joined: May 20, 2004 Posts: 2

I have also experienced this behaviour. Left my TT BT GPS in the glove compartment on Sunday whilst I played a round of golf. When I took it out 4 hours later it refused to turn on. The device was red hot and would not power up until it had cooled down. I have the latest version of the device which does not come with the car cradle. I have heard the cradle was discontinued because it was implicated in some device failures. Could it be that these devices simply overheated in the sun and the cradle was just a red herring?

JJ28 · Posted: Fri May 21, 2004 11:06 am Post subject: TT BT

I have the same problem this morning. I have left my Reciever in the car (gloove compartment) for a couple of days and now the BT light will not come on but the green light stays on.

This is the second BT receiver I have as the last one had the usual problems with the overcharging and got replaced by TT.

Bit annoying really as I have just got my update for TT3

ceesar · Occasional Visitor Joined: Nov 13, 2003 Posts: 5

It seems I've come across something similar...

I've had my TomTom Navigator BT kit since about October last year.

My first GT GPS device died, so I had it replaced in Dixons in December.

Since then, it's worked pretty much perfectly...except it appears to have problems on hot days.

I find that about 20 minutes into a journey on a hot day, the BT link between my iPaq and the TomTom BT GPS locks up, only a soft reset on the iPaq will clear it up.

Yet, on other days (and it *seems* to be only cooler days - I'm still trying to watch for the trend), it works perfectly...for hours and hours at a time.

Anybody else seeing this behaviour?

cheers,
ceesar.

MrT · Posted: Sun Jun 06, 2004 6:59 pm Post subject:

I assume the TomTom will work at up to 65C from its chipset which is perfectly normal for domestic devices. The cradle will work at up to 125C from the spec of its regulator chip which meets mil spec.

NMatthew · Posted: Sun Jun 06, 2004 9:14 pm Post subject:

I would have thought that the BT GPS would have been designed to work at at least 50C, but I have had problems at ambient temperatures much less than this. I am now convinced of a temperature correllation as it fails only on warm days and starts working again when it gets cooled by the air con in the car. I wondered if there was a connector expanding in the heat rather than a chip failure.

What's the fastest way to get it replaced? I need to use in on holiday in a few weeks. It came from TotalGPS originally, last December.

MrT · Posted: Mon Jun 07, 2004 7:30 am Post subject:

Your ambient temperature may be a lot lower than 50C, but inside the car the unit with heat from the Sun could rise much higher.

There could be a contact problem as you suggest or it could be that the battery does not like high temperatures.

The idea of the cradle causing problems is in my view just a red herring, all it contains is a 7-40V to 5V regulator that is reliable and will operate at high temperatures.

bigfatjohn · Posted: Mon Jun 07, 2004 7:46 am Post subject:

This is interesting. I'll try mine to see if my problems are heat related.

Should be easy enough to work out because, on a motorcycle, mine is sitting out in the sunshine all the time.

ceesar · Occasional Visitor Joined: Nov 13, 2003 Posts: 5

Yeah, I agree, the GPS unit *should* work in hot temperatures...but it's the only consistent trend I can find.

I'll see how I get on over the next few days...

Could people post here, to let us know if they do or don't have a problem with the GPS on hot days and when you bought??

I'll start...

New BT GPS unit from December 2003. Seems to suffer temp related problems.

NMatthew · Posted: Mon Jun 07, 2004 2:52 pm Post subject:

MrT, you're right that the temperature in direct sunlight might rise quite high. However, the product has been designed to sit on a dashboard and was supplied with a cradle to allow permanent fixing - so it ought to survive at least as well as the PDA which is also often left inplace and has not once had a problem. I suspect it's not a general problem or we'd have seem many more folk reporting problems, or does everyone take their GPS unit with them when they leave the car? The glove box and door side pockets are no good, it gets too hot there as well.

mark5290 · Occasional Visitor Joined: May 03, 2004 Posts: 42

I have just had my TT3 wired gps receiver replaced because it would not get a satellite lock, when not in use i store holder + gps receiver in upper glovebox (citroen c2) when it packed up on me the other day i noticed it was very hot in glove box, surely if they are meant to sit on dash they can withstand a little heat, if this one fails then i might buy a CF gps receiver.

NMatthew · Posted: Sun Jun 13, 2004 5:31 pm Post subject:

I sent the following to Tomtom and am now returning my BT device as it failed for the first time while driving - on the dash, but shaded.

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My Tomtom Bluetooth GPS receiver fails in warm weather. When the ambient temperature in the car rises my GPS receiver will not turn on. I get a single flash from the blue LED but the unit does not start - I cannot connect to my PDA, and I do not see a flashing green light to indicate a GPS location fix. When the unit is cooled by removing from the car and placing on a cold surface, after a while it will turn on and operate normally.

If while working the ambient temperature rises, the GPS unit stops providing location information (green light stops flashing) and the unit cannot be turned off. When the battery drains, and the unit is cool, it will start again.

I believe that this sensitivity to temperature indicates a fault with a unit since a friend has an identical unit that does not exhibit this behaviour. The temperatures are not extreme, just a warm Spring day in the UK. The unit has worked OK since I purchased it in November/December 2003, but this is the first time it has had to operate in warm weather.

----

Fault logged with Tomtom support, their remedy (full discharge) does not cure the problem with failure in high temperatures and they suggested a return, so that's what I've done.

Hope it doesn't take too long to get a replacement!

Neil

woodchip · Posted: Sun Jun 13, 2004 6:42 pm Post subject: Heat problem

I had some heat related problems and found that if I unchecked the infared connection it cured it.

NMatthew · Posted: Fri Jun 18, 2004 5:24 pm Post subject: Full marks to TomTom Repair

As I reported here on Sunday I obtained a returns number for my poorly heat-stroke suffering Bluetooth GPS receiver. Here'sa what happened next.

On Monday at 8am, I rang DHL to arrange a pickup on TomTom's account. At 10:30 DHL canme to the office and picked it up.

On Wednesday, the repair website showed "repaired".

On Friday, around noon, a brand new replacement receiver arrived, again by DHL. Interestingly the new serial number ix X4050XXXXX where the old one was X3070XXXXX, so perhaps there's been a hardware revision since I got mine last December.

I know TomTom's support gets criticised in these forums - and I'm sure many times rightly so, but credit where it's due, I consider 5 days door to door for replacing a dead GPS pretty good service. So there. Wink

Now we'll see if the new GPS survives warm weather any better, but it might be some time seeing as we've just entered a typical UK summer Sad

Neil

Chocki · Occasional Visitor Joined: Jun 16, 2004 Posts: 21

Well, I'll be putting TT's RMA dept to the test later as my bluetooth GPS has given up the ghost during a bout of hot weather.

It switches on and off but the green light just stays on and no further change.

I forgot to remove it from the dash one sunny day this week, and that's all it took.

It's still sitting here some 12 hrs later, that single solitary green LED, just on!.

OK, how do I go about RMAing this receiver please.

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