DIY CNC Controller Strange Sound Problem

I'm about as new to building cnc machines as one could possibly be, and if this is a dumb mistake or a stupid question, I apologize for my ignorance. Let me start at the beginning; Even though I'm only a year and a half out of high school, I didn't like any of the manufacturing jobs I've had in my area so I decided to build my own cnc mill and start my own business with a family member on the side. I decided to convert my Grizzly G0704 to cnc using Hoss's designs and recommendations. I ordered just about all the electronics I needed and built the mounting brackets for the stepper motors. I've never really done too much with electronics other than building a computer or household wiring, so I followed the schematics I acquired to the best of my ability and everything should be wired correctly. Everything powers up as it should, or at least what appears to be normal during a test. However, as soon as I power up the controller and it's connected to the pc via parallel port, it emits a high pitched sound like what electricity makes when it arcs across two points and causes the computer monitor to flicker a small bit, and makes the led on the breakout board get slightly dimmer. When unplugged from the computer it seems fine. I've seen no visible indication of sparks or anything out of the ordinary what-so-ever, and everything is grounded properly according to the schematic. Mach 3 software is installed properly on the windows 7 32 bit OS that I'm using. I have tested the port with a multimeter and the results seem to be what should be correct according to a video of a very similar controller build. The electronics that I'm using are as follows:

• C10 Breakout board
• 48VDC/12.5A Switching power supply
• Two KL-6050 Bipolar stepper motor drivers
• One KL-8060 Bipolar stepper motor driver
• 5VDC/5A switching power supply
• Nema 34 stepper motor 1200 oz
• Two Nema 23 stepper motors 570 oz

I still have more things to add to the controller like the c6 spindle control, but I need to make sure everything functions as it should first. I'm using 16g wire for everything except for the connections from the breakout board to the motor drivers, and the motor drivers to the stepper motors. For those I'm using 18g 4 conductor shielded wire. I've run out of ideas on how to fix this problem, and I don't know of anyone near me who knows anything about electronics let alone ones like this. Any help would be greatly appreciated, and I'm sorry if this is posted in the wrong spot.

It sounds like mis-wiring. Maybe you could reach out to Hoss with some pictures of what you've done, since you seem to be trying to follow his schematics. If you want someone local to come over and help you in person, it would help to share your location. You could also post your cry for help in the Mentors and Apprentices Wanted forum.

Troubleshooting is hard to do over the forum.
After verifying the wiring and controller settings, including Mach 3 port settings, etc, I would try one axis at a time and with a stepper motor just sitting on the bench. This way you get to test each axis before installing on the machine. If this works, then connect all motors (just on the bench) and test all axis again.
You may start with a slow RPM and low acceleration in the motor tuning section, and then gradually speed it up from there.