My phone recently crashed and won't turn back on.

Question

My phone ( iPhone 5c, IOS 7.3 ) recently crashed and won't turn back on. I randomly looked at my phone and there were green and red horizontal lines flickering. My immediate thought was to try to turn it off, so i could try to turn it back on. I held the home and power button down and the screen went black. When i tried turning it back on ( holding power button ) there was no response. For the past day, my phone hasn't been responding to anything.
(A day before the crash my phone cracked from a serious fall onto a concrete floor without a case I do not know if this has any relation to the crash )

Answer 1

(A day before the crash my phone cracked from a serious fall onto a concrete floor without a case I do not know if this has any relation to the crash )
It most likely has a lot to do with your crash.
Placing your device into recovery (DFU-Device Firmware Upgrade) mode:
Follow these steps to place your iOS device into recovery mode. If your iOS device is already in recovery mode, you can proceed immediately to step 6.
   1. Disconnect the USB cable from the iPhone, iPad, or iPod touch, but leave the
       other end of the cable connected to your computer's USB port.
   2. Turn off the device: Press and hold the Sleep/Wake button for a few seconds
       until the red slider appears, then slide the slider. Wait for the device to turn off.
              * If you cannot turn off the device using the slider, press and hold the
                Sleep/Wake and Home buttons at the same time. When the device turns off,
                release the Sleep/Wake and Home buttons.
  3. While pressing and holding the Home button, reconnect the USB cable to the
       device. The device should turn on. Note: If you see the battery charge warning,
       let the device charge for at least ten minutes to ensure that the battery has some
       charge, and then start with step 2 again.
  4. Continue holding the Home button until you see the "Connect to iTunes" screen.
       When this screen appears you can release the Home button:
  5. If necessary, open iTunes. You should see the following "recovery mode" alert:
  6. Use iTunes to restore the device.
If you don't see the "Connect to iTunes" screen, try these steps again. If you see the "Connect to iTunes" screen but the device does not appear in iTunes, see this article and its related links.
If this doesn't help, then make a Genius Appointment and take it in for service.
Note: When using recovery mode, you can only restore the device. All user content on the device will be erased, but if you had previously synced with iTunes on this computer, you can restore from a previous backup. See this article for more information.
If your iPod Touch, iPhone, or iPad is Broken
Apple does not fix iDevices. Instead, they exchange yours for a refurbished or new replacement depending upon the age of your device and refurbished inventories. On rare occasions when there are no longer refurbished units for your older model, they may replace it with the next newer model.
ATTN: Beginning July 2013 Apple Stores are now equipped to do screen repairs/replacements in-house on iPhone 5 and 5C. In some cases while you wait. According to Apple this is the beginning of equipping Apple Stores with the resources needed to do most repairs for iPhones, iPads, and iPod Touches that would not require major replacements. Later in the year the services may be extended as Apple Stores become equipped and staffed with the proper repair expertise. So, if you need a screen repaired or a broken screen replaced or have your stuck Home button fixed, call your local Apple Store to see if they are now doing these in-house.
You may take your device to an Apple retailer for help or you may call Customer Service and arrange to send your device to Apple:
Apple Store Customer Service at 1-800-676-2775 or visit online Help for more information.
To contact product and tech support: Contacting Apple for support and service - this includes international calling numbers.
You will find respective repair costs in the appropriate link:
iPod Service Support and Costs
iPhone Service Support and Costs
iPad Service Support and Costs
There are third-party firms that do repairs on iDevices, and there are places where you can order parts to DIY if you feel up to the task:
1. iResq or Google for others.
2. Buy and replace screen yourself: iFixit