Chosen Solution

When repairing a screen for one of my phones, the repair went nicely. After testing my phone I went to disconnect the cables, in doing this I forgot to turn of the phone. The phone refuses to turn on now no matter what screen is on the phone. I think it might be fried… please help.

Does it connect to a PC at all? It’s possible it still turns on but you may have blown the backlight

Unplug the battery? You should not be doing any repairs on phones without unplugging the battery.