Welcome to SF.
You'll hate these ideas.
You may have damaged your board, CPU, RAM, SSD, and/or GPU with the power surge.
Shaking the case? Something, somewhere is shorting/grounding out. Some cases (rare) have been found to have faults that cause this issue and would be difficult to track down.
Your board may not be fully isolated from the chassis. Remove the board and painstakingly check all stand offs are in place and each mounting hole has been screwed down.
Check the mounting on the CPU cooler, over tightening can do odd thing on some boards.
To help us help you would you please add your systems specs? Here's how: System Info - See Your System Specs Under System Manufacturer/Model Number add whether it is a desktop or laptop and whether self built. Log in to Seven Forums and you will be able to transfer the info directly to the specs page in your profile from within the System Info app.
After doing this your specs will be available in each of your posts. Click on mine in the lower left to see how it should look.
Full instructions in the tutorial.