OK, here is an update. First, pictures will not help. I found out that the missing ground wire went to a "clamp" around the yoke (from visual confirmation of a duplicate monitor). We have taken this monitor apart a few times and I have taken pictures everytime - precursor to mounting - and have never seen this wire connected there. Anyway, connected it up and turned on the monitor - 5 minutes and pop. Turn monitor off, 10 seconds, back on, 5 minutes and pop. Turn monitor off, 10 seconds, back on - still on been about 1:30 hours. What is the deal? Is it that the monitor needs to heat well first? I doubt that. Was the ground wire necessary and the monitor needed to discharge a couple of times to "reset" it. Finally, on the second pop, I was next to the tube and it didn't come from the tube. It was somewhere on the circuit board (where the power and vga plug in). I am letting it run in the garage for a couple hours to test and will update as soon as anything changes. In the meantime, any clues would be again greatly appreciative.
P.S. The Pop is more of a light snap. It just scares the ever loving piss out of me everytime it happens, so I was imagining it louder.