[Darbhara]

I lost my phone and used the Google app, Find my phone, to lock it remotely. When it was returned 36 hours later, the screen was black and nothing that's been tried so far will bring it to life. I spent a good hour on the phone with a Verizon tech, followed by another hour with a Samsung tech. Their collective prognosis was that something caused the LCD to die. I don't buy it. Can a software glitch in the remote locking cause it to do this? If so, is there a way to diagnose and repair without spending more than the phone is currently worth? (It is a 4 year old samsung galaxy s5).

Thank you for sharing your expertise!

[B. Diddy]

Welcome to Android Central! Can you tell that the phone is powering up when you try to turn it on? Does it make any sound or vibrations?

[Darbhara]

Yes. I can tell that the phone is working. In fact, when I was on the tech call, following instructions for trying to reboot the phone, i could hear that it had "but dialled" my husband's voice mail.

[chanchan05]

I find it unlikely that the remote lock will cause this, since it's still working in the background.

Was it stolen? Locking the phone may have caused the thief to throw it and led to the damage. Or if it fell from your purse, it could have falled in a way that turned the screen black. My brother's A8 (2015) fell from a shoulder height locker and ended up with a black screen but the phone still works in the background.

So it's entirely possible that the screen got broke during the time the phone was out of your hands.

If I recall, the S5 supports MHL. So you can get an adapter and plug it to a TV and you'll see the display of the phone.

But overall I think you'll need to have it repaired. I have no idea how much the phone is currently worth, but you should be looking at above $100 in terms of labor + parts. Some people say going to a Samsung walk in store with repair facilities is cheaper than having it picked up in their areas. I can't say because I am not in the US and there are like 5 Samsung official stores within 30min of my place some with repair facilities.

[can3gxw]

^ This is my thought exactly. How did you retrieve the phone? Did you lock it, then find it buried under a seat cushion one day, or was it lost out in the wild? This sounds like a broken screen. Whether it was broken by physical damage or even possibly water damage, your phone still works just not the screen. You will need to take it to a repair shop and have it looked at/replaced. This doesn't happen when you remote lock.