Display streaked glass not broken

Have you tried to test signs of life like toggling the mute switch on/off? If the battery is not dead but the LCD won’t display anything, that doesn’t always mean that the iPad isn’t on. If you plug the iPad in for awhile (rule out dead battery) and if the vibrating motor on the mute switch still works, then toggle the mute switch on/off and you will be able to feel that vibration. If you want to diagnose even further, you can always open the iPad, unplug the LCD from its connector on the logic board, then proceed to use multimeter and measure that connector on the logic board. I personally do not know where to obtain the normal values measured from that connector other than a shematic, measuring the same but working iPad, or someone on here that has access to schematics and values and knows which points to measure.