TomTom GO Failures - Was (TT Go gone phut)

stix · Posted: Mon Sep 27, 2004 8:11 am Post subject:

Hello all.... I'm new here, and new to Tom Tom as well. Finally decided to buy TT Go after a lot of deliberation, only to have it fried by the car charger after three days

Crying or Very sad

Now I have to work out how to get this replaced. Tom Tom have told me to send it back to the retailer telling them it was like that when I received it. The retailer tells me to deal with Tom Tom directly for repairs.

Evil or Very Mad

IW · Occasional Visitor Joined: Sep 20, 2004 Posts: 17

Hi stix,
I have every sympathy and would if possible take the unit back to the supplier. I was willing to do it in my case, as the supplier was not very far away, except that I know that it is a big shed with security on the gate and I doubt if I would have got inside.
My TT Go has been returned this morning (11.30 27/09) from Tom Tom Netherlands, picked up from me by DHL 15.45 21/09, and it is a new unit. The maps insisted on being re-activated, and despite telling me they had been activated once it was no problem after putting the new unit serial number in. Unfortunately a new power cord was not included, so I suspect that I have still got a faulty one, I am avidly following the thread on "Go DIY Power Supply" and may end up at Maplin.
The Tom Tom support number I used was the one quoted in a sticky on this site 08451 610009, they were very helpful. Good luck, let us know how you get on.

stix · Posted: Mon Sep 27, 2004 2:25 pm Post subject:

Thanks for your sympathy IW and glad you now have your Tom Tom back again. It was a sad moment when I realised what had happened and a long and quiet drive home without Jane!

I spoke to the supplier and they have agreed to send a replacement. I just mail it back to them and they will send me a new one..... all in all I guess both TomTom and the people I bought it from could not really have been better. Means I have a bit of postage to pay, but Rolling Eyes

Be careful with that in-car power lead though.

Zuke · Posted: Mon Sep 27, 2004 6:49 pm Post subject:

I'm trying to draw some conclusions from these threads. It does look like recently shipped TTGs may be delivered with defective 12v PSUs, since this thread is only a week old. Dave says the Pocket GPS World units are ok, presumably they're not recently acquired, but he's heard of other frying incidents. How many and is that with newly delivered items, Dave?

As I said earlier, I haven't used my week-old car PSU yet, and after following this thread, I'm not about to!

So two questions:

Any official statements obtained from TomTom? (Pocket GPS World would be in the best position to ask the question).

Anyone recommend an alternative 3rd party charger from Maplin or elsewhere?

Dave · Posted: Mon Sep 27, 2004 7:02 pm Post subject:

Zuke, I can't quote figures, but after talking to a number of retailers, teh return rate do seem to be higher than I would have expected (and them also).

The product is under warranty so I would use the supplied charger. Don't use a third party one, you don't know how much damage it will do to the unit.

It's not clear if it's the charger cables or the units themselves that are faulty, it could be a faulty charging circuit in GO itself, so using another kind of cable isn't going to help.

I don't know what TomTom's official stance on this is, apart from repair/return product at a quick rate and they have been quite quick from what I understand.

The units that have failed I am on the understanding have come from both earlyish and latish batches.

Zuke · Posted: Mon Sep 27, 2004 8:07 pm Post subject:

Thanks for the usual prompt response, Dave.

I think it's unlikely that the TTG unit is the culprit here as no one has reported a problem running from the mains charger. But I think you're right about using the supplied 12v charger, so I'm going to run a bench test on mine before risking it on a £400 device.

Like Old_Phil, I measured 5.18v from my charger on no load with my bench 13.8v PSU, so I'll try to find a Idea

to load it up to the rated 2w, and let it run for a few days. I'll post the result!

Dave · Posted: Mon Sep 27, 2004 9:17 pm Post subject:

I think probably there are two issues at heart here.

1) it could be alternators on cars piping back far too much charge to the battery and this is ending up inside the GO

2) faulty/iffy charging circuit on GO

stix · Posted: Tue Sep 28, 2004 8:21 am Post subject:

I would say it's almost certainly not a problem with the 12v supply in the car... works fine with other devices, and even if it was then the car charger should be fused in order to protect the device to which it is being connected. Either this fuse is faulty or is not protecting the circuit in a correct manner... i.e. it's in the wrong part of the circuit. The fuse may be on the input (12V) side of the circuit... if the step-down to 5V is not working correctly there also needs to be a fuse on the output side IMHO... this could be another point of failure.

The device was charging ok with the normal mains PSU, so it's unlikely to be a problem with the charging circuit either. I would say it's almost certainly in the in-car charger that something is faulty... a very cheap component that destroys quite an expensive one!

Anyway, mine has been sent back and should have another one soon. Think I might invest in a little multimeter before connecting to the car charger!

Old_Phil · Posted: Tue Sep 28, 2004 9:02 am Post subject:

Dave,

The originator of this thread (IW) later reported that his car charger was producing 12 volts output and not the specified 5 volts. He also says he found the fuse had blown.

Question is - did faulty charger go short circuit inside, stuffing 12 v into TomTom which then fried OR did TomTom go faulty, frying the charger and then blowing the fuse?

Mr S has stated that only car chargers are a problem - but he doesn't say why he is sure of this. The difference between the mains charger and car charger is that the mains charger uses a transformer to convert 240 volts AC down to 5 volts and then uses a bridge rectifier and capacitor to convert to DC and smooth. The car charger uses same technique as Bestyman to drop the 12 volts DC down to 5 volts. A fuse is fitted to ensure the charger stops if excessive current is drawn, say if a short circuit develops. The fuse does not appear to have saved the TomTom in IWs case.

I too had to send back my first TomTom but that was because the Li-on battery would not hold charge - my supplier replaced with zero fuss.

BTW, my money is on the culprit being a batch of faulty chargers - but then again I'm not much of a betting man!

MrT · Posted: Tue Sep 28, 2004 9:08 am Post subject:

There is always the possibility that somewhere in the chain, unregulated car leads were supplied. It would be interesting for anyone who has had this problem and sees 12V output to look in the lighter plug on the lead and see if there is a regulator inside (a three pin flat component about 8mm x 8mm x 3mm with possibly a metal plate slightly larger fitted as a heatsink).

Ade_ttg · Occasional Visitor Joined: Sep 23, 2004 Posts: 8

What we need in this situation is an urgent response from TT. I've had my TTG for 2 days and I'm sure as heck not using that car charger until clarification is forthcoming.

Incidentally, I wonder who actually manufactures the TTG unit itself? Does anyone know? (As I understand it TT themselves are not hardware manufacturers.)

Ade

delboy0754 · Posted: Tue Sep 28, 2004 9:07 pm Post subject:

I recently did a trip to the south coast from Blackpool, and had the in car charger plugged into the TT Go all the way there and back, with no ill effect. I would say it was on charge for 10 hours in all.

Come to think of it, since the initial charge when i first got it, back in July, it's never been on the mains charger, it's always charged in the car.

dodgydodgy · Posted: Wed Sep 29, 2004 11:18 am Post subject:

This is worrying me too - I often leave the TTG on charge when I'm out of the car (I've a socket in the boot which is live when the ignition is off, exactly for doing things like this). The last thing I'd want to do is come back and find my brand new car smoking.

Please - we demand an official statement form TT - and a recall if the chargers are faulty.

stix · Posted: Wed Sep 29, 2004 11:32 am Post subject:

This may reassure some of you... my TTG blew the very first time I used the car charger, and it blew instantly.... so if you've been using it ok with the in-car charger I would say you have no need to worry. If you've just bought one though, maybe find someone with a voltmeter to check you are getting 5V out of it........

Old_Phil · Posted: Wed Sep 29, 2004 11:42 am Post subject:

I've just re-read IWs original posting and it's not clear whether his GO blew the very first time he powered it via his car charger.

If it was a first time connect it leads credance to the view that this is down to a wrongly supplied charger unit - i.e. a 12 volt supply was included instead of a 5v charger. Then simply follow STix's advice and check that your car charger supplies 5v and not 12v.

If, on the other hand, IW's problem happened some time after he first connected power via his car charger then something is failing within the charger unit - and it may be a lottery as to if / when.

It would be good if Dave can use his contacts at TomTom to clear this up. I assume TomTom have done a post mortem???

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