Hi @eburg
If you haven't already done so, try connecting the tablet to a computer and see if it starts to charge.
If it doesn't, allow up to 2-3 hours to see if it starts to charge and also if it responds to the Power button or not.
If still no good, try replacing the battery and check if that resolves the problem.
I couldn't find a teardown video for your particular model, but here's a teardown [https://www.youtube.com/watch?v=hj4mvkpgGXg|video] for an Aura H20 reader that may help.
Also not sure of the battery required, but it may be a [https://www.google.com/search?client=firefox-b-d&q=pr-285083|PR-285083] (supplier examples only). Usually the battery model number is printed on the battery itself, if you wish to conform what is is. Search online for the ''battery model number only,'' (whatever it is) to find suppliers that suit you best.