A staff member will get here ASAP but in the meantime you should go through all of these steps - and write up what happened (not just “I tried all”).
Frequently this means your black ribbon cable has broken, which is a part you can order from the store if you’re out of warranty. If you’re still in warranty they’ll send you one if the logs support that supposition. They’re fiddly to replace, but many folks have done it successfully.