Why will my Kindle not open?

Donno if this will help but these are the issues and how I somehow managed to clear most of them on my Kindle HD fire (7 inch); I got mine about 2011 I think.
Problems I've come across with HD Fire; Glitches, blinking screen, very slow or stopping to work, Very slow loading, Freezing program and final; 1/2 screen (the worst of it)
* Slow or frozen is usually cleared by turning off (or flipping cover closed if you have an on/off type of case.
* Glitchy loading; Try to turn off or remove apps you don't use or rarely use. Many run in the back ground and take up memory, speed, bandwidth, and battery power. Check on youtube for help with this as it can be clumbersome.
* White out, is a symptom of over heating (like in a hot car or at the beach in direct sun light.) this is scary as nothing works. Dead giveaway is that the Kindle if very hot! Remove from heat source and take it out of case. Leave it on a FIRE PROOF table top like stone or metal. Use a cookie tray if you have one. Caution! if the kindle was heating up by itself while charging then remove from charger! Check if it's the right charger or charge with a lower power unit (300-500 milliamps) but do this AFTER it cooled down. Don't use a fast charger! Heat and Battery charging are a bad combination and will damage your kindle. I'm still using mine afer ....7 years? yeah the 1/2 screen clears up after the charge gets below 80%. Donno why this happens. It might be the battery may be swelling during certain power levels. It reall does not like being charged to 100%.
* For the errors listed above the final solution (besides returning it to Amazon) is to do a complete power shut down or hard shut down which involves holding the on/off button down for at least 30 seconds. This is like a laptop hard reset. Turn it back on after a minute and it will slowly power back up. Oh, forgot; Don't let the Kindle ever get to the point that it crashes completely. Once you get the final 5 min low battery warning. PLUG it back in to charge! You run the risk of corrupting apps and data. Some may need re-install.
* Okay the very last resort; Check that you back up all data to your cloud drive. Many kindle apps will do this already (like Checkbook) But if you have documents that were created on the kindle and not sourced out then have it uploaded to your Kindle (Amazon) cloud. Check the kindle help line for more info. OKAY: Now go to your kindle:
1. Swipe from top - down for menu.
2. Swipe menu to left to get to (+) More...
3. On settings choose Device.
4. Choose Reset to Factory Defaults.
5. If you WROTE down your passwords and account #'s and have them handy then proceed with "yes" to continue.
If not the STOP! and cancel, get out of menu and go find all your account info:
- Wireless access password (yours)
- Amazon Account Name, User ID, Password.
- You will need to reload all your apps that you currently use. Don't load stuff that you rarely use as you can always load them later as they reside in you amazon cloud account. You should not need to repurchase them. (though I've had problems with apps that require a "Key" code as they don't always work and some require 'proof' that you already purchased them.
6. Reset and let it go through it's power up and new customer initial set up. You will be surprised at what you forgot, even after a month. Try 7 years and you won't remember a thing!
* I'm reluctant to perform a factory reset as all my game scores, past history, and other stuff gets lost. Once I waited 2 years before giving up. (+$70,000.00 on Vegas style Solitare)
*************************************************************
*** NEVER EVER!!!!
***send the kindle through a Airport X-Ray machine! ***
*** this is what caused my 1/2 screen! It comes and
*** goes every few months. It's sporatic.
*** Seems to always want the wireless to be on as
*** once turned on it will clear the screen after the
*** battery drops between 65 to 35% charge.
*** I've been using my kindle like this for about 5 years
*** though I've switched to a 10 inch Android Phablet
*** now and found almost everything works once log
*** into Amazon. BUT you may find it cranky on
*** Amazon books as it won't reccognize my
*** Phablet. I still purchase books with my Kindle
*** which will automatically be available on
*** other devices as long as it's logged into
*** the same account.
*************************************************************
Aloha, ukeboy57
PS; if you have two kindles or more and it's for the (adult) kids then think about keeping them on one account as anything you buy (books) will also be available to them and visa versa. Or if saparate then you can loan them the book or purchase it as a gift.

always like to refer to Amazon help whenever possible. I copied their directions for this. Even if your's is not 5th gen it will work. You can also check specific info for your model by logging into Amazon.com Click help, then device help, click on you device and look through the info available.
Many issues with your Kindle, such as a frozen screen or issues with downloading content, can be solved by restarting your device. Help for Kindle Paperwhite (5th Generation).
Press and hold the Power button for seven seconds until the Power dialog box appears, and then tap Restart. Note: If the Power dialog box doesn't appear, press and hold the Power button for a full 40 seconds until your device restarts.

Dead battery. If you haven't charged it for several years it dies.
Unreparable although if you call kindle customer support they may give you a discounted price on a new or refurbished current model Kindle. They'll want your old one for parts.

This works for many frozen apps. Use the on button to turn Kindle off. Then wait a few seconds and turn it back on and hold for about 30 seconds until you see the kindle fire logo. Your app should open.

if it's left turned on, it will turn off when the battery runs out.

Make sure you have enough battery life to support the kindle, because sometimes it stays in the frozen state if it detects you have little battery life.

If this doesn't work, press , , and keys simultaneously (This is it's soft reset)

The last resort I would suggest is to do a hard reset. Make sure your battery is charged to about an hour, remove the cord from your kindle. Turn your kindle over and open the back, you should see the small hole under the word RESET. Get a paper clip, unwind it and insert the clip into the hole CAREFULLY and press for about 10 seconds. The screen should be blank, and it will restart.

Yes:

1. Get a watch with a hand for the seconds.
2. Slide and hold the power switch for 7 seconds. After about 5 seconds the power light flashes three times. After 7 seconds, the screen will go blank and the device is switched off now. Release the switch.
   
3. Slide and hold the power switch for 15 seconds (no more, no less). Do not hold the switch too long, the time window for the reset is not very big.
4. After releasing the switch just wait. The Kindle will reboot after a few seconds.
   

Try to slide and hold the power switch until after you see three blinks on the power LED. Should happen after ~5 seconds of holding.

if they sidebar works and you don't have an image on the screen, you definitely need a new screen. Amazon should give you a free replacement. If you're out warranty, you can get the part at Kindle Repair and there is a guide that shows you how to open a kindle and install parts at Kindle Repair Guide.