What is the make and model of the tablet? What issue are you having with it?
Does your charger work on any other device, such as a phone?
Ok, so it isn't the charger, unfortunately. Hold the power button down for 30 seconds. If it does nothing, try it again with the charge cord connected.
Do you see any physical defect with the charge port? If you shine a light in the port, do you see any foreign objects? Do you have any canned air to blow out the port?
When you plug in your charger, does it feel loose?
Move it around slowly and see if anything comes up on the screen. Pull it in and out slowly, angle it up and down, see if there's any sign of life
And another cable doesn't work?
So when you hold down the power button do you get even an 'empty battery' icon, or just absolutely nothing?
You have nothing to lose if its more than a year old and you're out of warranty, pry the back off and reseat the battery cable. I've done this in the past with iPad's with some luck. If you happen to have any rubbing alcohol around, clean the contacts with that while you're at it. Here's a couple visual references should you need them. Otherwise, time to get a new tablet. Reply if you have questions once it's open. If this isn't your cup of tea, may be time for a new tablet.
You got the back off already?
Gently pull back on that battery cable, pulling back a bit on one side, then the other. You may have to use a tool or something, you want to pull back on the black plastic part, not the colored cables. Once its out, clean the copper contacts if you have any rubbing alcohol, if not just reconnect it. Hold down the power button and see if you get anything with or without charger.
Actually, the instructions I'm looking at say lift gently on the wires to disconnect the battery.
This was a last ditch effort on a dead tablet. We had exhausted all other options, so it was worth a try. I certainly didn't want you doing anything you didn't feel comfortable doing. You can request a refund at any time by emailing***@******.***.