Gateway laptop wont connect to power

Question

I have 2 gateway ML6227b laptops. It started with 1 then the other started.The power connection doesn not work. Its not the battery as my son and I swapped batteries and i'd charge his up while he used my battery as his connection was the first to go. Then mine went and now we cant charge either laptop up or sit connected to a power sourse. Has anyone any ideas how to solve this please