To determine if your Nintendo Switch (serial starting with XKJ1) is “patched” (i.e., vulnerable to the Fusée Gelée bootrom exploit), the top number alone is not enough – but the full serial and the console’s manufacturing period give strong indicators.
Is My Switch Patched XKJ1 Top?
On the other hand, an unpatched Switch:
Hey fellow Switch enthusiasts!
The "proper piece" (correct information) for your question is:
- If you need a definitive answer and are comfortable with RCM/payloads: follow an up-to-date community guide to safely test for the exploit, or ask a trusted technician who knows Switch hardware to verify.
- If you prefer non-invasive certainty: provide the exact serial and model to a reliable community resource or check an updated serial-to-revision database to infer patch status.
- If your goal is homebrew and the unit is patched: consider whether you want to risk soldering/hardware modifications (not covered here) or sell/trade for a vulnerable unit.