Managing stiff PC on lightweight component

I am trying to use a stiff PC on my lightweight Pioneer DV-47Ai transport which sits on top my DAC which in turn sits on roller bearings which in turn sits on top of of a Machina Dynamica Promethean spring platform. Any thoughts on how I can make this work are appreciated. I like the performance of the stiff cable as compared to the limp cable it replaced. The stiff cable can be bent to shape.
If their is any way to support the cord from above Ive used Velcro .
I have the DV-45, and run into the same problem. I simply put a heavy weight on the front top of the player, as it also helps dampen some vibrations near the drawer/motor.

Not sure if this would counteract the other vibration control devices you're using. I use mine with a symposium-clone shelf, and it works great.

Good luck!
Assuming it's long enough go to Office Depot and buy some velcro. Shape the power cord to run along the back side of your equipment rack. Secure it to the rack leg in a couple fo places with the velcro. The type I'm referring to has the hooks on one side and the loops on the other and comes in about a three foot length. This type of velcro is great for dressing cables.
Would've been helpful to have pics of your transport / DAC setup in order to try something more related to your specific condition.

Anyway couple of thoughts to share with you are:
-Try using the roller bearings with two out of the three on the back half of your dack. So there would be less "turning" or displacement if there is side pull from PC. Best would be to bend to shape so the PC reaches the transport at the same level so it won't be pulling down or to the sides the back half of transport /DAC combo. This is a little tricky to obtain but doable. It might be needed to device a support for the PC that won't interfere with roller bearing movement "that much"; difficult to eliminate but could be lessened. Would have to play with slack and positioning to enable this.
Your feedback
Use a more compliant power cord.
We've run into stuff like that with customers using our Sonoran MicroBearing cables(which are heavy), and it usually works out well if you use cable-ties to fasten the cables to the rack/stand legs. This holds the cable to the rack, and in a good position(hopefully) to not interfere with any normal operation of your spring supported stand.

Actually, it sounds almost like a LP12 tonearm cable-dressing situation, and the cable needs to be securely fastened to the stationary part of the stand, while allowing a certain amount of "free-play" in the cable that leads to the equipment, so that it doesn't interfere with the spring suspension movement of the equipment platform. FWIW, if you get this right on a Linn LP12, then it sounds good, and if you don't, it doesn't. It could have similar effects on your platform.
I've used some big PC's before that fell out of the IEC jack, so I just tied some old shoelaces to the back of the rack using a sliding knot & adjust the tension as to balance the unit (if applicable) on an isolation device.

BTW, I found the smaller round style of lace works best.
I should have mentioned that I am not using a rack. The Promethean platforms just sit on the floor and are about eight inches in height. I do have the PC on some ceramic cable lifters and this helps some. I don't have digital picture capability at this time.
Use a more compliant power cord.

Been there, done that, didn't like the results as much.
Raise the cable off the floor until it's equal to the IEC jack. Since you've already raised them some, just stick something else under the lifters. You can also make a simple lift with strings & sticks in a variety of style, the easiest prob. being the Teepee style.

Also, wind some black electrical tape around the IEC connector until it fits snug into the jack.