I'm not sure why it wouldn't boot up, but yiu may be able to enter recovery mode...
Recovery Mode options vary for each Android device and can be different even on devices from the same manufacturer. Depending on your model of iRULU tablet, you may need to try other combinations, which include:
Home button + Volume Down button + Power button
Power button + Volume Down button
Power button + Home button + Volume Up button
Power button + Volume Up button
Power button + Volume Up button + Volume Down button
Power button + Volume Up button
Power button + Home button
Follow the steps provided below to perform a Hard Reset on your iRULU Android Tablet:
1
Turn your iRULU tablet off.
2
Press and hold the correct key combination to boot your Android tablet into Recovery Mode.
3
Release the power buttons once your screen turns on and the device vibrates.
Keep holding the other buttons for 10 seconds.
4
Your Tablet should now boot into Recovery Mode.
5
Scroll down to the 'Factory Reset' option using the volume down key.
6
Select the 'Factory reset' option by pressing the power button.
7
Now your Tablet will start the hard resetting process.
8
Keep in mind that once the process begins don't press any buttons and don't try to turn the device off.
9
Your tablet should now be reset