Hum X for CJ PV-10?

Joe, I know another A/V component is the culprit, but it's not easy to pinpoint, as I have audio, video, and computer gear all interconnected, and difficult access to most of the non-audio cables. The "cheater plug" on my preamp eliminates the hum, so, for the time being, it would be easiest to just "upgrade" to the Hum X, as long as it doesn't "choke" the power output to my preamp. I've ordered a Hum X, and will see if it degrades system performance in any way.

If you have the original power cord on the CJ, you need to start there as it has no ground wire. When I replaced mine, 20 years of copper corrosion was pretty nasty and it was basically lamp cord quality. Not hard for a DIY IEC plug update if you have the right power tools and protect the transformer. Or an electronics repair shop should be able to do.

Is there a ground screw on the back of the chasis?

Theres a ground screw for the phono but without earth terminal to ground, its a "floating" ground. There are PCB board grounds to chassis at the mounting screws, easy enough to rum a ground wire to one of those from a new IEC plug install.