Tom Tom One XL Schematic?

[comalco2000]

I have a frazzled TomTom One XL.   Two components have been fried off the PCB, but the bigger problem is I suspect that a track has been fused as when power is applied the power LED comes on, but the battery (connected on the opposite end of the PCB) isn't getting any voltage (and won't charge).    The rest of the unit doesn't turn on, which could be because it too hasn't got power - or it could be totally blown (hard to tell).    Would anyone have a schematic of a TomTom One XL so I can proceed with a fault find (or confirm the unit needs to be thrown)        Thanks.    Comalco2000

[pickit2]

What is voltage of the battery, most likely 3.7V
Then, what if you apply power to the battery end say about 4V via a 1A fuse, will it then work, and if it does, build the missing part of the circiut from power in to the battery. if it dont work bin it, or see what you components can reuse.

[sphinx]

i think that sometimes or lots of times they put a diode on power input thats if u use DC to protect device against wrong polarization so thats maybe the component that might have been fried thats if there is one of those, and most of the time a semiconductor get bad it gets a short, good luck fixing it

regards

[comalco2000]

Thanks for the ideas.  I've done the usual preliminary snooping and checking.  The internal LED comes on when powered via the car lighter lead, so I know I have power coming in, but there doesnt appear to be power at the battery connetor, and I would have thought that the 5v rail would go there to drive the battery charging.   The battery has a residual 1.1v on it, but doesn't charge over time (which supports the idea that there isn't power getting to the battery.   No diodes, but a SMD fuse (which is OK)..........  I've heard TomTom don't give out their circuits, but you can get them repaired, so there must be circuits around somewhere...........

[sphinx]

well there is allways the common capacitor problem too a very common issue today when they put inferiour ones in products of today, some products are better than others though. it can also be like that the charger unit is a small
switched power supply unit if capacitors are not ok that unit wont start, check them if not sometime they have switch diodes that can break down in that they can use a small transistor or IC to make the switch circuit that can get messed up. if u have an older product the batterie can be at fault as well since after a year or two it stops working since the batterie wont take any charge anymore.

well i am out of more ideas but that what i would have checked up too

regards

[comalco2000]

There are 3 wires on the battery connector.  I would expect that one is (say) 5v so the battery gets charged, and one the "charged" line from the battery, and ground.   The red "5v" line has 0v on it, and I deeply suspect that this is because there is an open circuit somewhere on the pcb.    I think th next thing will be to run a resistor from the 5v rail to this pin and see if the battery starts to charge.......then I'll know whether this red wired pin should be +5v or not...........makes sense that it should be, but you never know if designers follow logic.....or do things totally differently!     Lots of fun!

[sphinx]

hey again

the third wire from battery i suspect is a either a ntc, ptc or a simple temperature klixxon that senses temperature or just cuts power down if battery gets to hot, check that one too is thats not ok i guess battery wont be charged either.

regards