I'd put in a warranty claim. That sounds like a defective panel.I previously purchased a used / refurbished NX-5 on firmware 3.1 from Ebay that had intermittent vertical line issues that others have described. It happened at least 3-4 times in the first few weeks of ownership. I tried switching inputs and HDMI cables which did not resolve the issue. The only way to temporary fix the issue was to reboot the projector. I called JVC and was told the unit was defective and needed servicing, but since I was not the original purchaser and the warranty would not transfer over to me, I returned the projector to the seller without much issue. The first two pictures are from the NX-5
I replaced the NX-5 with a new RS-2000 on firmware 3.1 which I have had for about 6 months. I have been getting an intermittent single solid color vertical line defect. Its not as bad as the NX-5 issue, but it has happened at least 3-4 times already. I would toggle different inputs, but again the only way the fix the issue would be to reboot the projector. I have yet to contact my dealer / JVC, but I due think there is an issue that needs to be fixed. I don't want to go without a projector to get it serviced, but I think I will eventually need to get this addressed before warranty is over. The last 3 pictures are from the RS-2000. You may need to zoom in the see the solid blue vertical line which I marked with two arrows.
I don't know if it bad luck or not, but this is 2 out of 2 JVC projectors with similar defects.