Inspiron 13 5310, dim screen

Is it dim during the screen self-test (hold D through powerup to initiate)?

@ejn63​ I tried holding D through powerup but the self-test didn't initiate

Press F2 multiple times at powerup and go into Setup.  Is that screen dim?

@ejn63​ I have checked the bios, there’s no setting to help 

That's not the answer to the question.  You've complained about a dim screen.  The question is whether it's also dim when the system is sitting at a setup prompt.  If it is, you have a hardware problem.  If it is normal brightness at the setup prompt but dims under Windows, you have a Windows settings or configuration issue.

@ejn63​ it’s dim on setup prompts 

That would either be a bad screen or a bad power supply to the backlight (mainboard).  You may want to have a shop test the system to see which is the bad part before proceeding with a repair.

@ejn63​ I will do just that, it’s just that when ever I delete all display drivers and reinstall it, it gets brighter for a moment and goes dim

Best guess would be  that it's a power issue, which will require a replacement mainboard to solve.

Does the system correctly sense the AC adapter and is the connection between it and the power jack solid?