OK, I've downloaded the stock firmware, but how do I flash it in this stateDid you do the factory reset from within Android, or the recovery? If the former, enter recovery and factory reset from there. Then try again.
In any event, it appears you are in a bootloop, although the possibility does exist that the device is still resetting itself. If you've waited more than about fifteen minutes and it's still bootlooping, and you have already done the factory reset from the recovery, then you'll need to flash the stock firmware - if available - or else contact Onda.
tried to do so, but it seems soLong press the power button to shut the tablet off. Entering the recovery varies from one device to another. Most have you press and hold the volume up key while pressing the power button, but you'll have to do some quick research in the forums here for the correct method for your device.
Once in the recovery, you can then flash the stock firmware, assuming the stock firmware is in a standard zip file.