Fixppo did not solved iPad Pro 12.9 1Gen Black Screen

In January of this year I had the same problem, so I followed instructions on the Apple website to put the device in DFU Mode, and restore a December backup, and this solved the problem right away. But the problem came back in March, and I tried the same procedure, but it didn't work. So I decided to see if your software would work, since you offered a 30-day money back guarantee. And the problem has not been solved