970 Pro3 R2.0 problems

Is this a new build or one that was working and then stopped?

What are your full system specs? Please include power supply make and model, RAM make and model number and any extra peripherals you may be using.

If you are trying to boot into an OS from a previous build then there is your problem. You can't use an old OS install that was set up on different hardware, it will not have the correct drivers for the system to boot properly. It is always best to perform a fresh OS install with a new build/major upgrade. It is possible to make it work but it requires a few steps before moving the drive to the new system. I do not recommend using an old OS install on a new system as it will cause issues but if you must:

Boot into windows on the original system (whatever motherboard was used with the drive originally)

Run MSconfig.exe

Set the system to boot into safe mode on the next boot

Save and exit without restarting

Shut down

Install the drive on the new motherboard and boot

You should boot into safe mode if all went well

Run MSconfig.exe again and uncheck safe mode then restart

If it is XP then my steps will not work, your only choice then will be a fresh install. I need to point out here that the problem is not with the system but with the lack of drivers for the OS to boot. Before you change any more settings perform a clean install of windows. Don't forget to set your RAM voltage back to 1.5 as Wardog mentioned, you could damage your system with 1.7v.

Is the board new or purchased used? I see no reason why it would default to 1.7v unless someone used 1.65v RAM in it before you got it. It may have been tested at a store for example. Either way, no damage should have been done so soon.