Did you make the emuNAND first, like I said in this post:
If you did, and the emuNAND is a copy of your dirty sysNAND, you can just move the /Nintendo/ folder to the proper location, and you won't have to reinstall anything on the dirty emuNAND.
You must push fusee-primary or Hekate each time you want to want to boot into Atmosphere after powering off the system completely. It is recommended that you keep your Switch in sleep mode when you're not using it so you only have to do this if you're doing something like removing the SD card.
If you're looking for a more convenient way to enter RCM, I suggest installing AutoRCM if you haven't done so already. If you're looking for a convenient way to push a payload like fusee-primary, I recommend using an Android phone or buying a cheap USB dongle. Alternatively, you could install a modchip that will automatically push something like Hekate each time you power on the system, but most people don't find it worth the effort.
You should follow this guide to create an emuNAND if you haven't done so already:
https://nh-server.github.io/switch-guide/user_guide/emummc/partitioning_sd/
If you haven't done so, reformat your SD card with SD Formatter. Also, put your Switch into airplane mode to disable the wireless connections. If the error persists, I imagine it is hardware related.
Put the update NSP onto your SD card and try installing the update NSP using DZ Tinfoil.
https://tinfoil.io/
If you're using hacks with this NAND, you shouldn't be connecting to the internet without blocking Nintendo's servers, which makes using the eShop impossible. Otherwise, you risk being banned.
Assuming your Switch is unpatched, you need to pick which exploit you prefer. Do you want to use the RCM exploit (fusee gelee), or do you want to use the warmboot browser exploit (Deja Vu)? That will determine whether or not you can update your sysNAND.
If your Switch is ipatched, you cannot update your sysNAND. If you were able to install AutoRCM successfully, then you're obviously not ipatched.
