Problem vith VPI Scout and Dynavector 20XH

I have a VPI Scout with Dynavector 20XH cartridge, and after setting up the tone arm and cartridge according to the Scout manual, I noticed that sound was coming from only one channel. I looked closely and could not find any bad connections. When I touched the white cable at the cartridge I could hear a loud hum coming from one speaker. I checked the ground and they were well tightened, but I still head the loud hum when I touch the white cable. When I rub my finger on the needle of the cartridge, I did not get the usual loud sound from the speaker, I had to turn the volume up high before I could hear anything like buzzing sound when I touch the needle. The turntable was working fine before, all I did was to set it up again and adjusted the height of the tone arm per the manual, then this problem stared. Any ideas?
Make sure the lemo connector is aligned and seated properly. Try reversing the cables at the junction box. See if the problem jumps to the other channel. Report back.

I wish I had more to offer, but I would check once again to ensure all connections are made to their proper terminals, and are clean and tight. I always use a small amount of conact enhancer, such as Caig's ProGold, and then Mapleshade SilClear. Your problem sounds familiar to me, but I can't quite put my finger on it.

Best of luck,
Maybe one of the small filaments inside the cartridge is broken. That happens to me when I add a wood body to my denon 103R. Maybe this could be the reason
If you have a simple multimeter, you can check continuity between l and r wires from the cartridge end to the junction box end. This way, you'll know where the problem is.

Make sure you check both hot and ground.
I have checked continuity from junction box to the cartridge and its fine. I cleaned up all the connectors and RCA plugs on the preamp, the turntable junction box, and the base of the tone arm. I switched the cables on the preamp and only the right channel is working correctly. The left channel is very low and I have to turn up the volume to hear the music. I also switch the cable on the cartridge and only the right channel is working correctly. What next can I look for???
If everything is fine from the cartridge to the preamp, start switching wires from the output of the preamp to the input of your amp and see if the reduced sound moves. If it does, your preamp needs attention
I also thought of the preamp. I switched around the cables on the phono connection on the preamp and found out that both channels are good. The only suspect at this time is the cartridge, I switched the cables and the sound came from one channel. The only left now is to get another cartridge to try out.