I've spent hours with my rig today troubleshooting the heck out of it, I have 6 Nvidia GPUs on board mining for the past weeks nonstop now and today my 3070ti stopped working, not detected my hiveOS, I've changed riser no luck what else to look into? Dead GPU?
You need a test computer for video cards.
For these purposes I use an inexpensive computer on an AM3 socket with a good power supply unit. Also I recommend that you buy a multimeter. It is better to use Windows for testing.
Do you have a Hive OS on a USB flash drive or hard drive?