Powers down by it self then will not power up for up to twenty minutes or so

Hold the power switch for twenty seconds. You will need to slide the power switch along and hold it for twenty seconds before releasing it.

Your reboot screen should appear when you release the power switch.

Give your device time to reboot for a minute or two.

Turn the Kindle Fire HD back on.

Soft Reset:

1. Hold the power switch for twenty seconds. You will need to slide the power switch along and hold it for twenty seconds before releasing it. ...
2. Your reboot screen should appear when you release the power switch.
3. Give your device time to reboot for a minute or two.
4. Turn the Kindle Fire HD back on

Soft Reset:

1. Hold the power switch for twenty seconds. You will need to slide the power switch along and hold it for twenty seconds before releasing it. ...
2. Your reboot screen should appear when you release the power switch.
3. Give your device time to reboot for a minute or two.
4. Turn the Kindle Fire HD back on.

It could be a hardware problem. Half a screen not working doesn't sound good to me. I have a PaperWhite Kindle. I had another Kindle I dropped and it came up like yours, with half a screen showing the picture and the other half the screen showing white. It's now a paper weight.

You can try a total reboot by holding down the power button for about twenty seconds. Mine hangs up every couple months and the touch screen stops responding and the reboot by holding down the power button for about twenty seconds fixes it every time. It takes a few minutes. You have to sit there and watch the slow progress bar fill in as it goes through the re-boot process.

If this doesn't work, you might try removing the back cover, disconnecting the battery. Letting it set for minute or so and then reconnect the battery, re-install the back cover and try a normal short-power button push first and if nothing happens, follow it with the long power button push.

If it is turning itself off, it may be a issue with heat. Typically a product will shut itself down when hardware is irregular.

If the lock does not open after the oven has cooled down, then try this: First, unplug the range or shut off the circuit breaker for ten minutes. Plug the range back in or turn on the circuit breaker. Set the clock and try moving the door lock lever or opening the door. Next, set the self-clean cycle again and only allow it to work for twenty minutes. Cancel the self-clean cycle and allow the oven to cool. Gently try moving the door lock lever or opening the door

When your ignition coil get to engine temp. it will begin to lose its power, therefore your engine will eventually shut down, when it cools it will start up again,
Good luck

OK, this is not a good situation here. your Electronic Oven Control board is damaged. the logic sectors are faulty. The F-1 represents a major EOC failuer and, you will need to replace your EOC(clock) asap, if possible.