Dell XPS 15 9530 shuts downs On start up

Hello there

I have got a Dell XPS 15 9530 laptop that has been working with no major problems all those years. I only changed Dell battery and chargers. It overheats under pressure. I noted that and I dealt with it carefully.

last week while working I noticed the fans have sound and the laptop overheats too much, two days later the laptop suddenly shut down, I tried to re-start it , it gave me that the laptop needs to be plugged in to AC to recharge. I plugged the laptop into the ac and I restart again. It took only couple of second and it shut down. It did not even reach window 10 login.

I am a reporter working from home Now , there is a lot of pressure those days as you may know. I do not live in the United States or Europe, Dell’s official authorized Agent told me it will take two weeks till they answer me and tell me what is the problem In the first place due to the the pressure and the Coronavirus lockdown and work policy. My warranty is over. I used the laptop in photo editing and video editing.

I know that overheating and loud fan noise is due to dust. Last night I opened the laptop and I found Small nasty balls of dust in the two fans, I followed the tutorials online to clean them carefully. Interestingly after that , I restarted the laptop and i logged in for nearly 10 minutes and I got in to email notification and twitter notifications perfectly then a complete and sudden shut up after an error message of empty battery , the laptop was plugged in to the ac. The area of the graphic card and processor were extremely hot in that very short time.

since then the laptop plugged in the ac shuts down after one second or two second from start up , it fails to reboot and I do not know if I messed things up or not.

it is clearly a motherboard problem , right ??

I remember also now from couple of months ago , nearly half of the keyboard stopped working and I used a usb keyboard instead as well as a quick hack I found here : empty the battery then push the start button to reset The bios as I have read. It worked fine though I used the usb keyboard more. 

can someone tell me what should I do next?