Lenovo Legion 5 15ARH05 the RAM lid causes the black screen

Since 15 September, I had a keyboard problem on my Lenovo Legion 5 15ARH05 laptop. I opened a question to solve it, but had to send the laptop to the customer service at last. Then the motherboard has changed and the laptop came back. First day it worked perfectly, but today I had an another problem. When I try to turn on my laptop, the lights came on but the screen didn't. I tried to do AC Reset, restart, etc. But it didn't work. Then I opened the back lid of the laptop and tried many things. I plugged out the battery, HDD, SSD, CMOS battery and plugged in but it didn't work again. I thought

Question by etkmlm on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.