My cellphone Galaxy S4 fell out of my pockets, bottom lights turn on but my screen is black, if i shut it down and turn back on, can see the Samsung logo fade, is it possible to open my phone by using my pc, whatsapp, sms
Don't give up. I tried the method where you take out the battery, press the power button for one minute and then wait for five minutes before reinserting battery. Did not work.
I then tried the heat method. Disassemble the phone and unclip five or six ribbon connectors. Take the main board and heat it with a heat gun or close-up hot hair drier. Fast, with sore fingers, press the ribbon cables back into sockets and reassemble the phone. Did not work either.
I then reflashed the ROM using Odin. Not easy with a black screen but possible. Reflashed successfully, screen still black.
Then took out the battery and waited for six days: the phone then booted first time.
Hence, it looks like some bizarre capacitance is stored somewhere and needs time to discharge. I hope this info saves someone else's phone. Neil, Dallas, Nov 7, 2016