Mac goes to sleep when I connect the charger. There's no magsafe light

Greetings:

Sigh, i purchased this used macbook air last year, its a 2013 A1466.

Symptoms:

The laptop sometimes charges, sometimes doesnt. I've tried with several chargers (fake and original ones) and i see the same symptoms.

Sometimes i get the amber light and sometimes i just dont get a thing.

If the laptop hasnt been connected to the power outlet and i connect it, the laptop screen suddenly goes off, and the keyboard lights goes off too. The charger light is off too. If i disconnect the magsafe charger the laptop goes on again. I've tried doing shortcuts with the keyboard while the screen is off, and they work, and that shows the computer is not sleep or has shutdown.

If i leave it like this, plugged to the magsafe and wait from 15 to 20 minutes, the laptop suddenly starts charging just fine, i get some random "disconnects" (The magsafe suddenly goes off, and the screen goes off too) but then i get the amber light and then suddenly the laptop starts charging just fine, i can connect and disconnect the magsafe charger and i get the amber light on the magsafe, the laptop screen doesnt go off.

But this is obviously not a normal behaivor.

What i've changed so far:

- Magsafe charger: i've bought 2, 1 original and 1 fake charger. I get the same behaivor.

- Changed te I/O Board, same behaivor.

- I have made countless SMC resets, power cycles, pram and nvram reset, without luck.

At this point im just getting frustrated, any idea of what could be it would be great. Thank you for reading this!