I installed a picofly on a used V2 (Mariko) Switch. It glitched fine and I could initially get into OFW and Hekate. During my setup there was a period of intermittent connection issues on the eMMC lines (a long troubleshooting session with the connection dropping in and out), and after that the console won’t boot into stock firmware (OFW) at all — it reaches the Nintendo logo and then hangs, throwing error 2162-0002. The modchip itself works fine and the eMMC shows up perfectly in Hekate.
Important: I did NOT make a NAND backup before the corruption — the chip wasn’t installed yet at that point. So the only backup I have is of the already-broken state, which means I don’t have a clean restore point. I did, however, dump my keys with Lockpick, so I have prod.keys including BIS keys, plus BOOT0/BOOT1 and rawnand from the current (broken) state.
I’ve done a lot of diagnosis on the current NAND. The eMMC hardware is healthy (Hekate shows 100% life, all partitions present and correctly sized, full HS400 speed). I inspected the NAND in HacDiskMount and NxNandManager: PRODINFO decrypts cleanly with BIS key 0 (OK entropy ~5.4), so my console-unique data appears intact. SAFE, SYSTEM and USER all decrypt fine with their BIS keys (SYSTEM mounts and shows firmware NCAs and system saves; USER is empty, likely a fresh profile). BOOT0/BOOT1 read fine in NxNandManager with their components (BCT, package1, TrustZone) correctly identified. So nothing shows obvious gross corruption — everything decrypts and reads.
The corruption seems subtle (likely damaged firmware within SYSTEM, or a firmware state issue caused by the connection dropouts) rather than something I can clearly pinpoint. Since PRODINFO is intact and firmware is generic, I believe this should be recoverable by reinstalling clean firmware while preserving PRODINFO. Restoring my own backup won’t help since it’s the broken state.
My main problem: I can’t boot into stock firmware OR into an emuMMC (the emuMMC I made just cloned the broken firmware and errors the same way). So how do I run Daybreak (or the correct tool) to reinstall clean firmware when I can’t boot the firmware at all? Can I launch Daybreak via Hekate without a booting HOS, and target the sysNAND/emuMMC to reinstall firmware? What’s the correct current procedure to repair a non-booting Mariko NAND while keeping PRODINFO intact?
I’ve done the diagnostic legwork and just need help with the firmware repair step. Any guidance appreciated — thanks.