What could be wrong with Macbook?

Question

macbook

I decided to update AIR 2018 (a1932) to Catalina, but there were some troubles with it, the poppy periodically rebooted with an error. I rolled back to Mojave, there was clearly no problem such as on Catalina, but a couple of times the laptop still rebooted. I read everything that is possible, as a result, everywhere they advise to reset SMC or NVRAM. Began to do, reset SMC. Then he began to reset NVRAM and at some point the laptop went out and did not turn on again.
Further, when the power button is pressed, it does not show obvious signs of life, but if you press the power button, and then plug in the charge, it makes the sound of its connection.

I would think about the video chip, but there is one thing, but, in addition to the lack of a picture, there is also no backlighting of the keyboard keys, which suggests that the screen and video are still working, but something is wrong with them

I’ll take it to repair, the laptop is not under warranty, plus I figured it out and they won’t accept it in an authorized SC, so before taking it somewhere I would like to try independent fix options (not repair)

Answer 1

If still relevant:
1. Remove the back cover. There is a possibility that the battery is swollen.
2. Check the laptop with a stress test for overheating.