My 3ds xl has black screen but not 'dead' (with cfw)

it occurs when i play some 3ds game, and go to sleep mode. after i opened this 3ds but i failed and closed again (not physical shock like falling down or crash, just close the console) and display turns black and never return…

my 3ds has black screen. but as i said it’s not ‘dead’

it has blue light and orange light (wifi) on, and also hear booting sound.

also, when i press 3ds game depend on sound, it works!! also can control with

d-pad and button!!! but it also has black screen,

display works when recovery mode, and boot9strap mode, so i think this issue isn’t concern about motherboard short or wet

i googled and find this website and browse many things and tried, but it doesn’t work. here’s my attempt.

1) i pull out battery while 3ds turn on, and press power button

2) i close the 3ds when power on and reopen (in this time, sound off and bricked)

3) i pull out the battery, press power button couple of times, connect adapter, and put in battery and turn on

4) i use boot9strap mode and checked SVC/blur/ARM9 access and reboot

every thing doesn’t work.

and last thing…. recovery mode and update… this things makes me scary. as i said, i use CFW so my 3ds firmware version is lower (i can’t remember certain version)

if i update this firmware, it could be hard brick 3ds right? so i’m very scared and didn’t try it.

is it safe to update this thing? or can i rollback(down grade) to cfw mode??

what can i do other things on this issue?? please help!