My DSi XL won't power on after tear down. Blinking charger led

Hi guys! I had yesterday cleaned my nintendo dsi xl and mostly i wanted to clean the right and the left shoulder buttons. I did that in the first place and then i turned on my dsi xl. Then it powered on completely good and i checked them. One didnt work and then i teard it down again to reclean it but after that i cant power it on. When i put it to charge it has the charger icon blinking and it is not a battery problem as i have tested the battery in other dsi xl’s and it works completely fine. Can you help me?

UPDATE: I have also tested the screens and reseated them completely everything seems fine but it doesnt boot. :(