Updating switch firmware 8.1.0 to higher - black screen after nintendo logo

[retroboy14]

Tried everything and read everything i can before posting this thread.

Switch 8.1.0, sxos 2.8 with sxos pro dongle/license and nand backup.

I can update my sxos to latest version 2.9.4 and all is good.

I can install custom firmware with Choidujour and it seems to update fine - but when i reboot i only get as far as the nintendo logo - no switch logo, just black screen.

I then have to restore my 8.1.0 nand backup to get my switch to run again.

I have tried various version of firmware and sxos combinations but I just cannot get the switch to update beyond 8.1.0.

Any help would be appreciated - not sure what i have missed?

I've also tried updating emunand partition etc. and again the process is fine but cannot boot afterwards.

Thanks in advance

 

[imprezgc8]

Do you have a theme installed or are you using the SX autoloader?

 

[retroboy14]

No themes installed. I have tried everything i can think of - using sxos and atmosphere with sxos dongle and tegra rcm. i can install any firmware with choidujour but as soon as i try to boot afterwards i can't get beyond the nintendo logo. then i have to install my nand backup which puts me back onto 8.1.0. I'm sure i am missing something really silly but what - i don't know?
just tried downgrading and that works no problem. went from 8.1.0 to 7.0.0 and it boots fine. then tried upgrading to 9.2.0 with sxos 2.9.4 and i just get the black screen again after the nintendo logo.