How can I disconnect my iCloud on my device when it is not turning on?

You can absolutely still disconnect your item from your iCloud even if it is not powered on. Please use a computer, and follow the below instructions…

iPad Does Not Turn on Issue

iPhone Battery Issue

iPhone Power Button Issue

iPhone Charging Port Issue

AirPods Does Not Turn On Issue

Apple Pencil Does Not Turn On Issue

Apple Pencil Charging Issue

iPhone Black Screen / Does Not Turn On / Frozen Issue

iPhone Proximity Sensor Issue

Apple Pencil Battery Issue

AirPods Charging Port Issue

iPhone Boot Loop Issue

Samsung Does Not Turn On Issue

iPhone Camera Back Issue