Can't do much, this is often a hardware issue. You can try to do a factory reset, that will wipe the device and set it up like new, if it's a software issue that will fix it. You need to make sure you are OK with losing whatever is on the device when you try the restore, anything not backed up will be lost. If a restore does not help, you will either need to replace it or bring it to a shop to be looked at, but that can be as much as just buying a working tablet.