The only other thing I can think of, since you replaced the motherboard and adapter, is that the DC power jack has a bent or damaged pin. That would cause the type of problem you are experiencing.

https://www.dell.com/community/Inspiron/Dell-Inspiron-15-5570-plugged-in-not-charging/td-p/6061035

Hey thanks for replying, i will take a look about the power jack, i also forgot to mention that it sometimes starts charging again on its own until i disconnect the plug and re-plug it again and i start getting the plugged in not charging issue all over again and again sometimes it would start charging, any ideas?

I think dell can detect that the charger port isn't original.  I'm going through this issue right now. 

I used to have the same problem as you. But it turned out that it was just during the process of replacing the hard drive, I had poor battery exposure and the laptop didn't recognize it.

Tengo exactamente el mismo problema, pero mi laptop es la Inspiron 5575 , ya he reemplazado la bateria, el conector DC, he actualizado la BIOS a su ultima version, he cambiado el cargador, he verificado si era por problema de Software y nada. A parte de que me dice al iniciar el equipo que no reconoce los Watts del cargador, que conecte uno de 45 Watts o mejor, pero mi cargador está funcionado correctamente (ya lo he probado en otros equipos y funciona sin problemas). Ya lo que he hecho es pedirle una tarjeta madre para ver si mi problema es resuelto, pero la verdad, no pensé que este equipo me iba a salir tan malo. Actualmente la tengo que usar sin la batería conectada y sin la CMOS battery, ya que si la tengo puesta me limita la velocidad del procesador y no puedo ni usar el navegador. Espero y alguien con experiencia me responda una posible solucion para mí. Gracias de antemano.

Mine started doing this two months after the warranty expired. I have replaced the power jack, power supply, and the battery, all with OEM parts, and it still won't charge. Bios update also failed to fix. Worst PC I have ever owned. This is my last Dell.

It's a dell / charger issue. Dell throttles your laptop when you use a non original charger (and I can testify this as I tried over 4 chargers ) I had to import the only charger I found that exactly matches the original from us ebay to europe in order to make my computer charge again, and it did work perfectly. I have tried other fake chargers and they only kept the pc running without charging, I also tried original Dell chargers but having a different serial number than my original charger, and the same problem persisted. Long story short: you need an original Dell charger that matches your original charger reference number. There has to be something in BIOS preventing any other charger from working correctly. Shame shame shame. And I have to mention that this charger type is really bad, the pin gets damaged without any reason in 1-2 years. Currently my original charger is no longer charging correctly and it's working exactly like yours. So even with an original charger you're prone to experiencing the same issue

Hi ,I have a dell Inspiron. 5570 which is well maintained

Last week I did the monthly Dell update but it was getting all sorts of bother,.

It was saying Dell power management app to update and then I ran into real issues

I always have my laptop on AC but now AC won't even work ,

Today laptop was saying 0% ,low battery,power on battery ,

Nothing is working now ,won't charge or run off AC

Seems like issue with Dell Power management app

Check in Setup (F2 at powerup).  Is the AC adapter listed with its power rating, or does it show "unknown"?

Yes, that's exactly when all the problems started - when The Dell Power Management update happened. It caused so many failures. I spent money on new batteries, new adapters and hours and hours of troubleshooting and still none of the "expert" tips worked - nothing worked. Unfortunately, you can't even remove the update. What a mess.

Yea ,I just ordered a new power adaptor just to be sure but I'm totally lost now  as my battery has completely run out and the AC isn't working.

I was in the middle of removing all the Dell power management stuff from programs then the battery cut out.

I'll be really in trouble  if the new charger doesn't work,I'm out of warranty and will have to pay Dell to fix it likely.

Surely Dell should be liable for this if the updates they're giving are breaking our machines,that's what I'll be arguing anyway if I have to ring them 

Mine was showing unknown and I was getting a warning on boot up that the charger was not recognised ,I'm hoping my charger is just faulty.

Will find out next week when new one comes