Laptop can't be started up after opening it?

So my problem is this. I opened my laptop to clean the fan. I opened it normally (without violence) and closed it in the same way. I haven't plugged or changed anything. I really left everything as it was before. And now I can't start it anymore and I don't know why. The battery is full and I tried to start it with a cable, but it doesn't work either. Not even the light from the battery cable is displayed in the lower left corner. Does anyone have any ideas how I can fix it😭😭😭😭😭

Which notebook do you have?

Check all plug connections, maybe something has come loose without you noticing.

The brand is Acer but I don't know which number exactly. He is definitely more than 2 years old.

I've already been but everything was like before: /

Did you have to take out the RAM? Is it possibly not in the right place? Anyway, take it out completely and put it back in.

To remove, push the clips slightly to the side, then the RAM jumps up. As soon as the RAM is out, press the power button (for 1 minute, disconnect the battery and power).

Then reassemble. Insert the RAM at an angle and press down until the clips snap into place. Start anew.