My son’s Asus Memopad 7 HD would not power up or charge, and my earlier non-invasive solution wouldn’t fix it. Here’s how I opened it up to disconnect and reconnect the battery.
Always try holding the power button and volume down button first because that’s easier (see the link above for details), but if that doesn’t work, proceed to open the case.
While you’re in there, you can also fix an issue that may be causing the power or volume buttons to be hard to press or malfunction entirely. Dropping the tablet a lot makes this happen. If you have young children, you probably understand.
Another malady these tablets can develop is a battery with a question mark when charging. This will sometimes fix that issue as well.