Tomtom 7150 power issue

[SteveW10]

Hi, I have a 7150 Truck (one of many on our fleet of lorries) It suddenly stopped working, will not switch on at all. I tried all the usual, charge for 2 hours, hold the power button for 30 seconds and so on.

The power button lights up orange and no longer reaches green. So, i moved on to the next stage of investigating, opened her up and checked the battery voltage and it's only reading 2.85v, (should be 3.7v) when plugged in to a charger this doesn't change, it remains at 2.85v. The battery is a VF1C.

Would you start looking at component failure or battery failure? I have read that a Zener diode is an issue on other models?

Thanks for looking
Regards
Steve.

 

[dhn]

Try support, Steve:

United Kingdom
02079 490 134
Monday - Friday: 9:00 a.m. to 5:30 p.m.

 

[SteveW10]

Thanks for the reply, I don't think support are going to help with repairs suggestions. They'll just want £200 to repair It!

 

[dhn]

Try googling 'SatNav repair shops in the UK" then..........

 

[canderson]

I suppose there are three questions involved:

1) Is the source voltage adequate?
2) Is the battery impedance so low that it is pulling down the charging circuit such that you're getting an abnormally low reading? (I should suspect the battery would be a bit warmer than normal, too!)
3) Is the battery charging circuit just no longer working at all, or certainly not regulating to a 4.3V level?

Separating #2 and #3 is most readily done by swapping in a new battery pack. Observe it's voltage and then see if it drops during operation with an external supply. If so, you've got #3... not good. If life improves, you had #2.

 

[SteveW10]

Thanks for your reply, it was a very sudden issue. Literally overnight it stopped working. I'm only getting 2.85v at the battery with and without the charger plugged in. No power is making it through the charging circuit. I have tried different charging leads, mains and car. Nothing is getting through.

Got a feeling it could be a lost cause. But still worth a try before condemning an expensive item!

 

[canderson]

Indeed. Would hate to bin something that costs that much. Still, 7 years of regular use on a nav device is pretty good.
Prior models have been known to take out a diode in the charging circuit. One would have to inspect the board to see if there was some indication that this has happened on your unit. If you're game, look for a charred part with a number like D1 or D2 or D3 on the silkscreen. If you spot something, and are either handy with a soldering iron or have a friend who is, you might be able to resurrect it for the price of a 10 penny diode.