Hacking Question Can I downgrade without a NAND backup?

[Jellykrop]

Hi,
My external hard drive decided to go skydiving without a parachute and I just lost my 4.0.1 NAND backup that I did before upgrading to 6.1 using ChoiDuJour, and I would have liked to re-do one.

My Switch is currently on 6.1 with autoRCM enabled. I was wondering, can I downgrade to 4.0.1 without a NAND backup using Choi, disable autoRCM (since it corrupts boot sectors, if I'm correct) and then do a NAND backup of my Switch on 4.0.1 before upgrading it again to a higher firmware (6.1 or 6.2)? My fuse count is 4, my Switch came on 4.0.1 and was never updated officially.

I would rather ask the community before doing anything dumb and complaining of a brick right after
Thanks!

 

[Kubas_inko]

You can downgrade via choidujourNX.
Also, you can upgrade to 7.0.0/1 (but there is no difference yet if you stay on 6.2.0)

 

[Jellykrop]

You can downgrade via choidujourNX.
Also, you can upgrade to 7.0.0/1 (but there is no difference yet if you stay on 6.2.0)

Alright, but is the method I described feasible? I wasn't sure I could downgrade without a NAND backup safely (only using ChoiDuJour)

 

[Kubas_inko]

Alright, but is the method I described feasible? I wasn't sure I could downgrade without a NAND backup safely (only using ChoiDuJour)

I told you yes. You can use choidujourNX to downgrade to keep your stuff or use choidujour to rebuild your NAND and make it clean.
Downgrade via choi -> remove autorcm -> do a backup -> do whatever else you want. But, it won't be considered a clean backup (depending on what were you doing on your NAND).
If you want to rebuild your NAND, thus make a clean NAND, you can use normal choidujour, but you would lose everything on your Switch.

 

[Jellykrop]

I told you yes. You can use choidujourNX to downgrade to keep your stuff or use choidujour to rebuild your NAND and make it clean.
Downgrade via choi -> remove autorcm -> do a backup -> do whatever else you want. But, it won't be considered a clean backup (depending on what were you doing on your NAND).
If you want to rebuild your NAND, thus make a clean NAND, you can use normal choidujour, but you would lose everything on your Switch.

Oh I get it now, thanks. And what is the difference between a "clean" backup and a normal one? Am I going to get in trouble later when restoring it? I never done any customisation to my Switch besides updating using Choi, running a CFW and a few homebrew apps.

 

[Kubas_inko]

Oh I get it now, thanks. And what is the difference between a "clean" backup and a normal one? Am I going to get in trouble later when restoring it? I never done any customisation to my Switch besides updating using Choi, running a CFW and a few homebrew apps.

Clean one has no traces of any "warez" activity. It is just like a brand new switch NAND. Nothing installed. Nothing changed.

 

[Jellykrop]

Clean one has no traces of any "warez" activity. It is just like a brand new switch NAND. Nothing installed. Nothing changed.

I see, thanks for your help

 

[Zumoly]

Also it doesn't hurt to have more than one backup. Why not do one of your actual fw?

 

[Jellykrop]

Also it doesn't hurt to have more than one backup. Why not do one of your actual fw?

Great idea! I'm gonna do both.

--------------------- MERGED ---------------------------

When I backup my boot partitions with Hekate while autoRCM is still enabled, does it backup the corrupt ones or the clean ones?

 

[Zumoly]

Great idea! I'm gonna do both.

--------------------- MERGED ---------------------------

When I backup my boot partitions with Hekate while autoRCM is still enabled, does it backup the corrupt ones or the clean ones?

It will backup the current state: corrupt ones
Unless of course you deactivate it for that purpose.

 

[Jellykrop]

It will backup the current state: corrupt ones
Unless of course you deactivate it for that purpose.

Ok thanks My NAND backup of 6.1 just finished, I'm about to downgrade to 4.1 and do the same thing again.

 

[Jellykrop]

Huh... this is bad... I just downgraded from 6.1 to 4.0.1 and now when I click on "boot CFW" on SX OS it shows the Nintendo logo, then "an error has occured" and it shows me my serial number and my firmware version "4.0.1" and nothing else... How can I recover from this please?
Error code : 2002-4315

 

[Jellykrop]

Hi,
I just downgraded from 6.1 to 4.0.1 using ChoiDuJourNX (no fuses were ever burnt, my fuse count is 5 and the Switch came with 4.0.1 out of the box).
Now when I click on "boot CFW" on SX OS it displays the Nintendo logo, then "an error has occured, Error code : 2002-4315" and it shows me my serial number and my firmware version "4.0.1" and nothing else... How can I recover from this please?
I have a NAND backup of 6.1 that I did before downgrading, and access to Hekate, but autoRCM was enabled so I don't know if my boot partitions are valid...

 

[Kubas_inko]

Just out of curiosity, try different CFWs.

 

[Kafluke]

Huh... this is bad... I just downgraded from 6.1 to 4.0.1 and now when I click on "boot CFW" on SX OS it shows the Nintendo logo, then "an error has occured" and it shows me my serial number and my firmware version "4.0.1" and nothing else... How can I recover from this please?
Error code : 2002-4315

What did you do to downgrade? Did you use a nand backup? Did you also flash boot0 and boot1? You need both of those to downgrade properly.

https://gbatemp.net/threads/psa-sto...ou-know-what-youre-doing.531861/#post-8520674

 

[blahblah]

Update to 6.1.0. SxOS has issues with downgraded systems that are on very old versions.

 

[Jellykrop]

What did you do to downgrade? Did you use a nand backup? Did you also flash boot0 and boot1? You need both of those to downgrade properly.

https://gbatemp.net/threads/psa-sto...ou-know-what-youre-doing.531861/#post-8520674

I used ChoiDuJourNX, browsed the 4.0.1 firmware folder containing NCA's, installed it and turned off the console. Then when booting I held vol+ and inserted my dongle, the SX OS boot screen showed up, and I clicked on "boot CFW", then this error message appeared.

 

[Jellykrop]

Update to 6.1.0. SxOS has issues with downgraded systems that are on very old versions.

I only wish I could, but I don't have access to ChoiDuJour since I cannot boot into CFW.

 

[blahblah]

I only wish I could, but I don't have access to ChoiDuJour since I cannot boot into CFW.

Boot Atmosphere.

 

[Jellykrop]

Boot Atmosphere.

I will give that a try, thanks. Just wondering, in order to boot into atmosphere, should I remove the boot.dat file from SX OS and replace it with Atmosphere's? I am using a Mac, so no payload injector for me, I am relaying only on the SX Pro dongle.