The power button stopped working. It will not turn the tablet off/on, so I kept it on the charger and had the screen time out after 15 seconds. I forgot to put it on the charger yesterday and it turned itself off. Now it's fully charged and I can't turn it on.

SOURCE: Nokia N800 Tablet

I had the same problem with the n810. I was using a non-oem battery and the connections were a loose fit causing the battery not able to charge.
If you take the battery cover off, hold the battery firmly in place. Connect the charger and make sure battery is charging, then press the boot button. If it boots and stays on, then shuts off when you stop holding the battery. Then you probably have a loose connection or a bad battery. Also try cleaning the connector with a pencil eraser and alcohol.
I had to wedge tthe battery in place. You can find a spare battery with a desktop charger on Ebay for around $10US.

SOURCE: non responsive (battery is fully charged). Screen has frozen up.

There is a reset button at the bottom (insert paper clip in pinhole). If all attempts trying to unfreeze it fail, you may have a logic board issue. Are you sure the Kindle powers up? Try to power up your Kindle with a different battery. If that fails, 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.

SOURCE: When turning on my

Try doing a hard reset. Just take the battery out or hold down the power button of x amount of seconds

SOURCE: My Dell Streak 7 Tablet will not charge. When the

I can't charge my sell streak 7 (no orange and green color appear when plug in) moreover the unit can't turn on also.

I tyr hard rest also but no response at all

would you please suggest me how to do it

SOURCE: my galaxy tablet GT-P7510 wont turn on its fully charged

Hold down power up button until it starts. It can take up to 30 seconds before it restarts.