Hello everybody! About a month ago I bought a used non-working tablet, I thought “oh, now I will just flash the BIOS and get a working tablet”, but I was soooo wrong
I found that the resistance on the 1.8V power line is too low. I removed the processor and the resistance returned to normal.
I ordered a processor from aliexpress.
After that, the tablet turned on and there were no more problems.
So, be careful, use known good chargers, buy good OTG hubs, do not overheat devices during use (playing games and charging at the same time can really overheat the motherboard).