A Kernel Power 41 error means "unexpected shutdown". From your description, I think it is not from a power outage or holding the power button down. You could have a hardware problem. I suggest these steps:
Overclocking: Disable overclocking to see whether the issue occurs when the system is run at the correct speed.
Check the memory: Verify the memory by using a memory checker. Verify that each memory chip is the same speed and that it is configured correctly in the system.
Power supply: Make sure that the power supply has enough wattage to appropriately handle the installed devices. If you added memory, installed a newer processor, installed additional drives, or added external devices, such devices can require more energy than the current power supply can provide consistently.
Overheating: Check whether the system is overheating by examining the internal temperature of the hardware, especially the GPU.
Defaults: Reset the system back to the system defaults to see whether the issues occur when the system is running in its default configuration.
