About a week ago I have taken my phone (s7 edge) off the charger, used it for about a minute, the phone turned itself off and the screen went black. I have tried turning it on, nudging the battery by holding volume down and power, yet nothing works except a solid blue led light.
I want to discharge the battery since that is what a bunch of sources suggested. Can I just put a resistor over the 5v line of the usb or can I do something that doesn't involve cutting a usb cable?
Be careful with that advice you have been given, as you will write off the battery from a safety perspective if you drain it down to a certain threshold. If you want to dispose of the battery you may wish to drain it - carefully. However in your instance, you more likely want to establish whether the phone is the issue or the battery. I have had a phone before that shorts out batteries so we can't always assume the battery is to blame. Unfortunately in your instance you have what I would call a built in battery so you have to decide whether you want to try swapping out the battery or replacing/repairing the phone.