The battery cannot charge after connecting to a power source

One possible cause is that your battery is low or the battery can no longer hold a (good) charge. In this case, the TomTom is shutting down because there's not enough battery to keep it running, even though it is plugged into a power source.

To determine if the battery is the cause, try to charge the TomTom battery .... using a (USB) connection to your computer, or a direct power source (i.e. while the TomTom is not being used). Let it charge for a few hours until the batter charge indicator shows that it is fully charged (or just leave it charging overnight).
Then, unplug the TomTom from the "charger" and power it up. If the TomTom (battery) doesn't hold a (good) charge, the device will shut down within a few minutes, e.g. 10 mins or much less.
When you (then) plug the device into a power source, and it doesn't stay on (i.e. it keeps shutting down after 10 seconds), you can safely conclude that the battery is the cause of your problem.

When you connect your laptop to a power source to charge it using a charger, the battery light will start to flash in RED color. It will turn to GREEN when your laptop is fully charged, so you can remove your charger from the power source.

I know my 990DSL wont charge if the serial cable is plugged in.

Do you live in Europe> Typically power supply should only be 110 - 115V
Battery is simply no good any longer. If you can get 2 yrs from a battery you're doing good.
Try removing the battery and using the power supply and charging battery when not in use. Replace battery.
Hope this helps

Your PC connection must always come via UPS, and your UPS will always keep charging.

UPS Power cable should be connected to DC, and your PC power cable should be connected to UPS.

And this way your PC will always be safe.

The blinks usually mean low battery. Did you connect your power cord and try starting up. Or if you have a different problem. Do as follows

• Disconnect battery and connect only the power source
• Disconnect power source and connect only the battery
• Connect both and test if the battery is charging up

This will help us know if there is an issue with the battery or the power adapter.

does it show that it is connected to the power source? the plug? if it is then, clean the terminals to the battery and the computer. make sure computer is off and disconnected from power source. if that still doesn't fix it then it is something with the connector in the computer.

Install the battery (see above steps).
Connect the AC adapter to the printer and the power source.
Notes:
Before using the printer on battery power, fully charge the battery for
2.5 hours.
You can print photos while plugged into the power source.