Differential encoder hard crashes the PC MESA7i77

Hi everybody! I am struggling to get the MPGs working with my 7i77. These are differential encoders, and are wired into TB4 (z axis and x axis). Whenever I go to launch LinuxCNC, the computer crashes without warning like something is shorting or there is some hardware problem. 
When I unplug TB4, LinuxCNC will at least launch. 

Are there any jumpers i need to move around on the 7i77? The MPG wheels are supposed to run 5vdc…

I would check the 7I77s 5V supply, my guess is that it droops
when you connect the MPGs, either from a wiring error or
too much current.

Does the 7I77 have 5V power supplied to TB1?
 

I am using 5V from the 6i25 card. I had also wondered if there was a wiring error somewhere, but I tested the MPGs with a multimeter found no errors. I double checked the wiring and everything is in the right place....so, this time I unplugged the terminal blocks and -you guessed it- LinuxCNC still crashes. It must have been a sad coincidence that when I plugged in the MPGs things went bad.I am using a Linux 6.1.0 -19-rt-amd64 kernel, which I just updated. That didn't fix the crash issues.I can open and play with everything just fine if I use a simulated machine, just completely crashes as soon as I try a non-virtual machine.I cant make heads or tails of the crash log. 

I have 5v power from the computer. I unplugged ALL the terminals on the 7i77 TB3,4,5,7,8) reinstalled LinuxCNC (worried about kernel issues) and the darn thing still dumps me when I launch the program. 

I feel like I’m getting to the limit of the things I can do to make this work. Any help is welcomed. Anybody have any ideas??

Hey thanks for the fast reply. I ended up powering the 7i77 with a dedicated 5v power supply. Flipped all the appropriate jumpers on the 7i77 and 6i25

i would also like to point out that I removed the terminal blocks for ALL the encoders, drivers on the previously mentioned TB…so it can’t be shorted or drawing too much power because everything is disconnected! 

I started to wonder if my 6i25 was dead. I don’t see any LEDs light up on it when I power up the PC. I also can’t find it with lspci