Force starting (resetting) needs more than 10 seconds, mostly. The instruction says: at least 10 seconds, so it might take more time than these. Try the procedure again, maybe it will show the logo earlier than 10 seconds (not very likely), maybe it will need 20 seconds and longer.
If force starting doesn't help, take a look at iTunes on your computer. The latest version should be 12.5.2. If it isn't, update iTunes.
Update your computer.
Use a different USB port when you plug in your iPad. Disconnect every other USB device.
If iTunes still doesn't show your iPad, try another computer.
Your last option would be to contact Apple or take your device to the next Apple Store, so that the experts there can take a look at it.