That’s a BSoD...you may be fucked now...I've check the cable and I believe you're right. The cable/connecter seems to be damaged. (please have a look at my picture below and let me know if you agree.)
In the meanwhile I desoldered my hardmod wires to make sure I wasn't making any short circuit. That wasn't a good idee since my N3DSXL isn't booting anymore. The blue power led turn on for a few seconds and then turn off while making a click/pop noise. Did I "brick" my N3DSXL?
@TurdPooCharger knows those better than I do. Though, I would recommend, check to see that you haven’t bridged any of the contacts you’re soldering to.
And the cable doesn't look too bad...show me a picture of the connector, up close, please.