I just want to take the time to mention and thank @lily2012
After asking a ton of question which were always answered quickly and with the guidance given I was able to get my switch to boot and update the firmware so that it would boot with and without RCM.
Although lily2012 is a new member like me I have a feeling he/she is going to be a great asset to this community.
Hi, I am new to the forum, this place is a great resource as I've recently purchased a broken Switch from Marketplace and have been fixing it up. It was dead due to water damage but I have managed to bring it back to life however I am now at the stage where the experience the OP has here is exactly what I have.
I was interested in how this was resolved as it seems the solution was handled offline...
As a summary, same as OP, Switch will not boot, connect it to PC with TegraRCMGui, it doesn't get recognised, take EMMC module out and RCM OK comes up. Then I can put EMMC module back and push a payload. I can also use Jig and RCMLoader with EMMC attached and push a payload. I can see all the details of the EMMC module with no issue, I can back it up etc. I have built an emuMMC on SD card but when I try and boot into atmosphere, I get the logo flash for a second and then screen goes blank nor can I boot into OFW. I have rebuilt the FW and tried wiping but still can't boot into anything. It did manage to boot into the console once but not after that.
I know this post was 2 years ago but was curious if you remembered how you managed to resolve this...