Hacking Lost SD card, secondhand 3DS doesn't boot, don't know which hack was used

[haxorious]

I have this 3DSXL that was hacked by the previous owner. It's been sitting unused for 6 months now, and the SD card was lost somewhere during that time.
Now it only flashes the blue power light and can't boot. I strongly believe it's because of the missing SD card containing the hack, because everything was working fine before I lost it.
I know nothing about 3DS(XL) hacking, I have no idea which hack the previous owner used, and I don't have his contacts anymore. All this reading about Luma and A9LH and CFW is giving me headaches.
It'd be nice if someone could include a specific course of action for me to follow, instead of reading aimlessly about hacking. I just want to restore everything to factory settings and play with the cartridges that I purchased.
Thank you for your time and assistance.
Update: It was sold to me on 1/1/2017, so the hack version must be prior to that.

 

[Hayato213]

We can't really help you much without knowing what method was used to hack the 3ds.

 

[Hunter]

you'll need to goto https://github.com/AuroraWright/Luma3DS/releases
download v7.0.5 to see if it's A9LH if so, upgrade using the below

if v7
try doing https://3ds.hacks.guide/a9lh-to-b9s
to upgrade it to B9S

try v7.1 if it's that upgrade B9S - https://3ds.hacks.guide/updating-b9s

try v9.0 if it's that just do the finalizing


then do https://3ds.hacks.guide/finalizing-setup

 

[haxorious]

Thank you for your responses. A quick update should it be helpful, the 3DSXL was sold to me on 1/1/2017, so the hack version must be prior to that.

 

[Hunter]

Thank you for your responses. A quick update should it be helpful, the 3DSXL was sold to me on 1/1/2017, so the hack version must be prior to that.

there are 3 choices for the hack, do what I said and you'll end up with a working system

 

[haxorious]

there are 3 choices for the hack, do what I said and you'll end up with a working system

I was just wondering how could it be V7.0 (released april 2017) when the 3DS was hacked in 2016. But I will try doing what you said. Thank you for your help.

 

[Hunter]

I was just wondering how could it be V7.0 (released april 2017) when the 3DS was hacked in 2016. But I will try doing what you said. Thank you for your help.

because the person that owned it before you may not of upgraded the hack

 

[Hallowing]

The idea is if it is A9LH any boot.bin file should work