Unit will not power on. Light on the charger does

When the charger is plugged into the unit, look at the main menu screen. If the charger is working correctly, the green battery icon in the upper right-hand corner eill go out. If the charger is plugged in and there is a light lit on the charger but you see the green battery icon in the upper right-hand corner of the screen on the main menu, then the unit is on battery power and the battery is not getting power from the charger. Common problem with these units are loose rear USB ports. More information can be found here:

http://www.sharc.net/gps_charger_repair.htm

• Turn the Navman off by holding the power button in the upper left corner of the device until the screen goes blank.
  
• Plug the unit into its charger using the USB port on the bottom of the unit. The battery indicator light next to the power switch should turn orange, indicating that the device is charging. Once the light has turned green the charge is complete. If the light does not turn on, verify that the car charger is plugged into a working outlet.
  

No! you are further ahead replacing the unit.

The traffic receiver is in the car charger cable. The charger should have a red light on if it is getting power. If the light is on and the unit is not charging and you have no traffic, the charger cable is bad. If the light is off, then either the fuse did not fix the problem, blew again, or is somehow not sitting properly in the charger. Another thing you can check is by using the unit in another vehicle. If it works fine there, then the charger is not making good contact with your vehicle outlet for some reason. You will probably have to buy a new traffic receiver charging cable.

First check the power light on unit when attaching car charger, if there is nothing some chargers have a fuse in the end of the charger, but if there is a green light there could be something wrong with either your battery or your unit

if the light is on the bit that goes in cigar lighter in car then fault in unit or wrong charger being used, i f no light on charger the replace/check fuse in charger ( unscrew tip ) and or check cigar lighter working in car

I'm afraid you have the green light of death. This happens when the car charger delivers more power than the TomTom can handle and it blows a couple of diodes.

Mine does the same, the light comes on on the charger, but not on the TomTom unit itself. There is clearly a loose connection in the cable somewhere as you can twist the flex and make it work, although this is not very reliable.

I just use a USB charger from an old phone instead.

There are 4 reasons why your unit is behaving this way:
1. Charger is the problem.
2. The docking station is the broken.
3. The battery is broken or not accepting charge.
4. The actual unit is the problem.
It is very hard to tell which one is causing this to happen.
Let us do some troubleshooting first:
1. Plug your charger in an A/C outlet and make sure the red power light (left) is lit, otherwise the charger or the docking station is broken.
2. You can test the charger with a multimeter. Unplug the charger from the docking station and measure the voltage across the outside and inside, it should register more than 5 volts DC. If there is a 5Volt DC the docking station is the problem otherwise the charger is broken.
3. If the red power light is lit and the status light (right) is lit too, your docking station is broken.
4. If the red power light is lit, dock the unit into the charger, the status light (left) should turn red when your battery is accepting charge or turn blue when your battery is fully charged.
5. If the status light will not lit at all (while the red power light is on), tap the screen while the unit is docked on the charger. If the unit will become alive, you need a new battery otherwise you need a new unit.

12 hours is very long time to charge, the status light should turn to blue in less than 2 hours especially for a new battery.

Could be a loose contact at the connection between the wire and at the gps unit.

Think the green light must be on at the charger port and also on the gps unit.

This green light can be found near the power button on the gps unit.