720 Just Died this Weekend, Guidance needed..

[PleazerAppliance]

So the background on my Go720. I bought it new in late 2007 and have logged nearly 300,000 miles on it. Maps are US, & Canada. It contains the original battery, although it's barely able to hold a charge, I keep it connected to the power adapter at all times when in use. I purchased the Bluetooth remote, but hardly use it, I purchased the traffic antenna kit at the same time and always use it. In the last 8 months or so the mini USB connector on the 720 has been finicky in regards to how well the cigarette power cord is plugged in, but this does not apply to the original charging dock. I am using the original TomTom cigarette power supply which plugs into the antenna adapter, then the traffic unit plugs into the 720. When I'm done using the 720 for the day, it comes inside and gets placed on the PC charging dock. As of 3 days ago on Friday the 720 was working fine, it remained in the PC charging dock until I removed it this morning, that's when I realized that the green light was no longer lit. Once placed in the vehicle and connected to the car charger, it was apparent that something was wrong because the green light was still off. The 720 does work off battery when powered on, but the battery is very weak and the unit self powers off shortly after booting up. Thinking that a spent battery might be the issue, I installed a new one that I already had. No luck. I opened the unit up looking for any signs of component damage but found nothing. A close visual inspection of the mini USB revealed no signs of cause. I am suspect of a possible PC surge via the USB port to the charging dock as being the issue. I usually log out of my Win7 64bit, then just let the PC go to sleep in about 1.5 hours, this gives the Norton time to do any last min scans. I did just purchase a working but used mother board which I will install when it arrives, but prefer to resurrect my original mother board instead...
Any guidance would be great.
Thanks, Chris...

 

[Arno]

Welcome to TTF, Chris.
The advice/dialogue will start once the moderator canderson sees your posts.

 

[canderson]

Over time, even the USB miniB connectors can get a bit wonky, especially with frequent plug/unplug activity or (oops) the occasional drop while the cord is attached. They're a lot more durable than the newer USB microB, but still - not indestructible. So it's possible that not even a visual inspection is telling you the tale. The fact that the car charger connector had been acting wonky for a while may be a clue. No fun replacing those SMT connectors, either, unless you're experienced at it.

As far as the motherboard itself goes...

Go back and have a very close look at component D8 on the board. Assure that it looks clean and new, without signs of being overheated.

 

[PleazerAppliance]

Yes I agree on the mini USB port, but I never experienced a connection issue with the charging dock. Once it's in the dock, it's still and always showed signs of receiving power. The only event that occurred over the weekend was the daylight savings time change, doubtful that had any affect on the matter, but all other functions with the PC have been the same for the last 4 years. I'll check that diode location provided it's marked on the board to see if there are signs of trauma. Although I do have a Hakko equivalent solder station with a micro syringe tip, I do not have a hot air gun for the SMT work. Does the mini USB port carry a standard part number of any kind, something I can find at Mouser or an equivalent? This appears to be the one actually...

http://www.uctronics.com/100x-pin-female-mini-usb-cable-smt-socket-connector-p-154.html


The SM leads seem more accurate on this one.
http://www.ebay.com/itm/100x-5-Pin-Female-Mini-B-USB-Cable-SMT-Socket-Connector-/390301587241

 

[canderson]

I do like the look of that 2nd one. I find that one of the main differences are front/rear offsets on the shield lugs, but that one looks good from here.

As for why it may have worked in the dock and not with the cable. Even the cable side can start to deform over time. I more often encounter this problem with the microB design - the miniB is a bit more robust.
You don't need to worry about hot air for either the diode or the USB connector. With skill, both are large enough that they can be managed fairly readily by hand.

If D8 is an issue (and you could take a meter to it while things are powered), be advised that it is a 5.6V zener.

 

[PleazerAppliance]

Well, the mini USB receptacle on the 720 is definitely at fault for a sometimes poor connection, all I had to do was back out the plug a bit for steady connection while in the vehicle, I'm concerned about the loss of power during it's rest in the docking station on the PC, dropping it in on Friday, then realizing this Monday the green light is dead. I would like to replace the mini USB connector, but when I do, the unit will still be dead till I find out the exact componant that went bad. Power is a problem as the original battery will only last long enough for a partial boot, and the replacement battery is already dead. I believe that D8 is the diode for charging? Other failure symptoms that I have read describe that the green light is on, but the battery does not receive the charge. The PC goes into sleep mode after 2 hours, which discontinues power to all USB ports. Is there an avail schematic for this unit? Although a replacement board is on the way, I'd prefer to fix this one, since I never used the backup that I made a long time ago, I have no idea all of what it contains beyond my favorites, and if it includes all my settings too.


I did find this interesting site,

http://www.tomtomrepairteam.co.uk/


These are listed as the correct replacement...

http://foxpcparts.com/mini-usb-port...m-tom-go-520-520t-510-510t-720-720t-730-730t/

 

[canderson]

You definitely want to fix your own board if you can -- if for no other reason than that the serial number is embedded in a memory area that you cannot access, and your maps are all keyed to your original serial number. You can't put your old maps on a new board.

I don't know for sure that you have any problem other than issues with the USB connector. I'd start there to see if things come back to normal first.

 

[PleazerAppliance]

I was reading another thread in a different forum regarding the serial numbers, but they called TomTom and had them work it out. I did buy 2 of the USB mini receptacles from the last seller Fox PC Parts who is located in the US.

 

[canderson]

I'll be interested to see how TT tech support sorts that. I suppose the fact that your 720 is as old as it is might sway them a bit.

Let us know how you get on with the USB connector, and whether that turns out to be the only issue you had. Since the issue popped up (almost) concurrently between dock and car adapter cable, I'd like to think that we don't have to worry about those. Still, if you have another miniB cable hanging around after you replace the connector, I'd test them all.

 

[PleazerAppliance]

Well, let me re-phrase a bit, It worked fine last Friday, and at the end of the day it was placed in the PC dock as always, the green light came on as always, I've never had connection issues in the dock. By Monday I noticed the green light was off, and that was it. I've wiggled and jiggled the connector while connected to a charger, with the board un-installed in my hand, not so much as a flicker out of the green light. Now, yes the mini USB on the 720 is in need of replacement, but with it making it to the PC dock and showing it was receiving power, then suddenly over the weekend is goes dead without being disturbed, I still question other causes.
Lets say that there was a shard of metal from the shield, like a chip of chrome plating that decided to lay across the USB leaf tabs and cause a short, I would feel that something like that would happen the second I dropped it into the dock, not hours later sitting undisturbed. I do have a Seagate external 1TB USB drive connected to the PC 24/7, unless it's less sensitive to a voltage spike, it's fine. So that may trash my theory of a USB spike. And I think that the USB voltage from the PC stays consistent, so there shouldn't be an increase in charging voltage, in the event that the original battery decided to call for more charging power. I could absolutely be wrong, but I think replacing the mini USB socket may not change the situation. They are on the way none the less, I bought 2 in case of an install issue. Are there any schematics avail to show the power flow in?

 

[canderson]

No schematics were ever released for these units, no. Inconvenient - causes a lot of unnecessary reverse engineering trying to get them fixed.

 

[PleazerAppliance]

When all else fails, there are these NOS ones possibly? At that price they had better be more than NOS....
http://www.amazon.com/TomTom-4-3-In...&qid=1426209944&sr=8-2&keywords=TomTom+Go+720

 

[canderson]

Wow -- hard to imagine anyone having any stock of these units, much less new! I don't know anything about this Wall Street Photo outfit, other than they seem to be playing on the name of the 'venerable' 47th St. Photo.

If you are really dedicated to the features on the 720 for some reason, let us know which features those are, and we may be able to suggest other units that would cover them (e.g., 730, 930 are virtually identical, then there are 740, 750, 940, 950 with a few twists). If nothing else, it may open up your availability of used units.

 

[PleazerAppliance]

I'd just prefer to fix my 720 due to familiarity of the last 7 years of using it. Using an I Phone 6 Plus for everything from Google maps, and phone calls through the Bluetooth is not cutting it, I drive about 200 miles per day, and my 720 has logged a little over 300,000 miles already.
Mini USB connectors did not arrive today as the sender entered the wrong info on the shipping label through stamps.com. and not he correct shipping info that I entered on my order. So that will have to be sorted out. The replacement mother board is on the way, and I purchased a complete 720 set up with car charger, PC dock, original map disk, storage case, windshield suction cup, and users guide. Said to be working, shown as powered on. That will give me a complete spare, and more spare parts. I may contact the seller on the NOS 720 as well...

 

[canderson]

With luck, you'll find a fairly recent map on the 720 board, but there's no telling.

One BIG piece of advice. Once you have this stable of 720s assembled, do NOT try to use the same email account for ANY of them. Each unit/board needs its own email account or Home and TomTom's server can get very unpleasant.

 

[Arno]

Each unit/board needs its own email account or Home and TomTom's server can get very unpleasant.

@PA
Unless you want TomTom to mail news letters to you, these eMail addresses can be fake ones but should be in the right format, at least (e-mail address removed).
These addresses will only be used to identify your device once you are connected to TomTom via HOME.

 

[PleazerAppliance]

Well, we have a glimmer of hope. First part arrived today, used but shows signs of obvious life. The shipping error has been corrected for the 2 mini USB connectors on the 720, those will be arriving soon, and the EBay seller marked the complete used setup as shipped today. Just a quick scan of the board reveals there seem to be circuit location identifiers, hell if my eyes can see them, and I'm not old! So does anyone know the location of D8?

 

[canderson]

Well, we have a glimmer of hope. First part arrived today, used but shows signs of obvious life. The shipping error has been corrected for the 2 mini USB connectors on the 720, those will be arriving soon, and the EBay seller marked the complete used setup as shipped today. Just a quick scan of the board reveals there seem to be circuit location identifiers, hell if my eyes can see them, and I'm not old! So does anyone know the location of D8?

Under the black tape, as shown:

 

[PleazerAppliance]

Yup, lifted the tape, can easily see that one. I'm so use to through hole technology, how do you even follow the traces on this board?

 

[canderson]

With a meter and my 6X jeweler's 'goggles'. I haven't seen my 20 year old eyes for ... well, a lot of years.

So -- how does D8 appear to the 'naked' (or otherwise!) eye?

Through-hole? THROUGH-HOLE? Please, bring it BACK!