Screen shows nothing and charging sound is looping

You're right already---it's either the screen or the logic board. Both failures can show this behavior.

There is no substitute for trying another screen on the phone, and then if that fails to solve you'll need to send it out for backlight repair.

Post water damage is almost certainly backlight repair. The backlight coil is like a cat when it comes to water.

There is a lesser known cause which is the proximity sensor next to the front facing camera. When this sensor fails the screen can go blank. I look at the looping charger sound as a separate issue if the proximity sensor is out. Replacing the screen (like a cracked screen that was otherwise working) has preceded the onset of these same symptoms many times. This supports the idea the symptoms can be related to the screen, connectors or possibly some other disturbance to the phone while replacing the screen. I've read about success re-installing a new screen, cleaning the connectors, and the phone came back. Also, taking out the blank screen and testing in a known good phone showed the screen to be OK. This could again support need for re-installing or cleaning the board connectors. There is no single answer. I have a phone in similar condition. I'm going to test with some spares from a friend and see what develops. I'll re-post in a week or two with good or bad results. Best of luck!

Iphone 5C

I usually dont find answers on here and this timw was no different! !!! Thanks for your help everyone but its better not to post anything if you dont know first hand how to resolve the issue because i literally spend six hours reading the same thing over and over!

The real solution

°Pop the screen up

°Take the two little screws out the bottom

°Take screen off

°Pop off lcd wires in top right hand corner

°Wait 20 minutes....

°Put everything back together

Sounds hard? Really isnt...whats the worst that could happen ???

It only inovles two screws so its nearly impossible to mess up....no money??? Try this trust me!!! But once it xome back on! Sell it...its not worth the trouble if it happens again