No power,brand new,neverhas turne on or shown battery if plugged in

Onn Tablets are a Walmart Special brand sourced in China at the lowest price point for maximum profit. It is for good reason that Apple iPad is the brand leader in tablets.

Take it back, it is faulty.

Although Sleep Mode does cause some battery drain, it should last days if not opened. If it is plugged in, it should remain at 100% ALL the time. It inbuilt charging regulation is broken. Get a refund and buy a brand name tablet, Samsing, Acer or iPad.

Hi try plugging in charger & holding down >> just the power button for awhile if u have no luck u might have to disconnect the battery ....cheers

Make sure it is fully charged. Hold power button down for about 10 seconds and wait if nothing comes up press power again for half a second. Still nothing? Then put it on charge, it should show that it is charging with a light of a picture on the screen. If there is no sign of charging, wait about 3 hours leave the charger connected and press the power button again for about a second and wait for it to turn on or for the picture to show it is charging appears on the screen, (make sure the charger is on and connected) . Press the power button again for another 5 seconds and wait. sometimes it takes a little while to turn on, especially if the battery is very flat. Other things to try are check the charger on another device e.g. another table or a phone if you can and try another charger on the tablet if they are compatible, (usually the same plug is o.k, check the voltage is the same. most chargers are USB 5v). It may need a more powerful charger than most small phones,. you can try plugging the USB cable into a car charger or USB 3.0 port on a computer. 2 amps is common for most tablets. Apple may be different, hard to be exact without knowing brand etc.
If all else fails see the retailer

If it won't turn on, doesn't mean that the battery isn't charging! I had one of those, them and other cheap brands alike are real bad about not wanting to turn on! If it is in a wrap around carrying case, take it out, plug it in, now keep pushing the power button, this can take several minutes with luck it will snap out of sleep! This worked for me on 2 different brands!

press and hold the power button 10 sec ?
Press and hold both power and volume down buttons for 10 seconds, then release vol. down button while holding down power button for another 10 seconds, before releasing.
plug to pc and wait to be recognized?
take out the battery so that samsung fully discharge so this should help reset replug the battery.

I've had the same problem with my RCA 10 inch tablet. I have charged it, tried the hard reset, used different chargers and even different outlets, and held the power button on for 60+ seconds with NO RESULTS! My recommendation is to contact RCA, which is what I am doing, and request an immediate replacement if yours is still under the 1 year manufacturers warranty. If you look these tablets up, you will see (as I have found) that this is apparently a common problem with the tablets. Wish I had known that prior to purchasing!

If this is brand new why waste your time, take it back to your retailer for exchange.

Lithium ION battery may be damaged by extended use. If available try a warranty replacement.

Sorry to hear/read this.
First, try get a new charger and plug your Google nexus 7. Suspect a dead battery with no charge left on it.

Otherwise, confirm your charger isn't just lighting up whereas it isn't delivering any charge current to your device.

Next to try if your ac charger is confirmed good is to attempt replacing the battery; at the store, have them insert a compatible/similar battery and then try power on your device.

NOTE:
New batteries at the point of purchase have some charge on them; sufficient to power on your device.

Device not power on, DON'T PURCHASE NEW BATTERY. Obviously, you don't have a power/battery problem.

Device power on, then you either have a battery that has failed or that your device's charging port needs to be serviced or repaired.

Please post update/feedback asap. Thanks