Chosen Solution

I am trying to restore my iphone 12 to factory but it seems to be stuck in recovery mode . When i force reset the screen goes completely black no matter how long i hold the power + vol button for nothing happens. I left it for 24 hrs last night and was able to get a charge then tried to force reset but it went black again. i tried another apple cable in my pc with itunes open i think the update/recovery screen came up for a second but then disappeared. I dont think its the battery as it only happened when i tried to force reset.

The black screen means it is in DFU mode not recovery mode. ITunes should recognise it in either state. I would suggest trying an update with 3uTools software and make sure your iTunes is up to date. If you can I would try connecting it to another PC or Mac.