Won't Turn On, just blue light and clicking sound

Hey,

I worked on my Nintendo 3DS XL (I replaced the “joycon” and cleaned the b-button) but after reassembling it, it won’t turn on again.

I can see the blue light for a few seconds, then the bottom screen flashes for split seconds, simultaneously I can hear a clicking/popping sound and afterwards it will shut down.

Is there any way to fixing this problem?

Thanks in advance,

Christoph