iPad with black screen but backlighting still on

As described, you may have a screen hardware failure that will require repair. However, there are some steps to try before reaching this conclusion

If your iPad is unresponsive, connect your iPad to its Power Adapter and allow the iPad to charge. Then, while still connected to external power, try a forced-restart:

Force restart iPad (models with Face ID or with Touch ID in the top button)

If your iPad doesn’t have the Home button, do the following:

1. Press and quickly release the volume button nearest to the top button.
2. Press and quickly release the volume button farthest from the top button.
3. Press and hold the top button.
4. When the Apple logo appears, release the top button.

Force restart iPad (models with the Home button)

Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.

If iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen. Or if your iPad isn’t working correctly after you restart it, see the iPad Support website.

If you continue to experience difficulties, you will need to seek assistance directly from from Apple Support. You can contact the Support Team using the Support link at top-right or bottom-left of this page. Alternatively, you can initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044

You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad:

Genius Bar Reservation and Apple Support Options - Apple

As you are well outside of Apple's limited warranty, unless you have statutory rights within your country/region that require Apple to offer a refund outside of warranty, the likelihood of Apple entertaining a refund for a device that you have been using for a year or more is very, very unlikely.

As for repair of your iPad, for practical purposes (and in lieu of repairing and returning your own iPad), Apple usually exchange the iPad for a renewed/refurbished iPad of the same model and specification. The cost of the exchange is the same as would otherwise be charged for repair. When exchanged, the replacement iPad is yours to keep.

You can establish repair cost in your country/region here:

iPad Repair & Service - Apple Support

If you have benefit of an active AppleCare plan, the repair cost is reduced to a small excess/deductible fee.

You can use Apple’s mail-in repair service, or you can arrange repair via the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP):

Genius Bar Reservation and Apple Support Options - Apple

I too face same issue with my iPad Pro, I was watching YouTube and suddenly screen went black,

I too lost trust on iPad and it cannot be repaired by Apple Authorised Service Centers.