The console is not powering on

Hi!

I purchased a used 3DS XL 2015 recently. I knew that it was not functioning. My plan is to repair it and have fun with it. The symptoms are the following:

• When the device is turned on, the blue led lights up as a normal operation.
• Neither of the displays turning on.
• About 5-10 seconds later the bottom screen faintly flashes once, then the LED is turning off.
• No popping sound from the speakers.

The troubleshooting that I did:

• I checked the battery it holds the charge well. Currently it is at maximum capacity, ~4.1V.
• I checked the fuses on the board, they’re not shorted.
• I reconnected all ribbon cables.
• I checked for water damage, by checking the water damage indicator stickers on the main boards.

Do you have any ideas what might be the issue? The repair guides that I could find in the internet are useless for this issue. I know iFixit has a good community.

Best regards,

István