You guys nailed it.  It was totally the bivert chip.
Everything works great now!  Thank you!

I agree, I think if it's fixable, it's the bivert thing. Resolder all those joints. Check for continuity between the top part and the other side.

I put in a bivert pcb like that on a dmg. Had some issue with it that I can't remember right now. I resoldered the holes and the top left one seemed to be my issue. After that it all worked.

I thought the same thing initially, but the problem persists when I hook up a completely separate front PCB
Just to be doubly sure, I hooked up the original front to an unmodded back and had no problems.

Maybe check the connection ribbon cable between the two PCBs?

I'm finishing up a commission for someone right now and have run into an odd problem.  Maybe someone can help.
(This mod has a backlight, a bivert chip, and a 1/4" pro-sound kit)

At one point, I was having no problems.  I had everything wired up the way I planned to have everything while I was painting the shell separately.  Once I finished painting the shell, I needed to de-solder the pro-sound kit so that I could insert the jack.  After soldering that back up, I am no longer getting any image on the screen.  To me, this seems quite odd since I don't think the screen and the sound are at all related.  I'm certain that the ribbon cable and the polarizing film aren't responsible since I've taken the front PCB and hooked it up to a spare unit.  This tells me that something on the back PCB is causing the problem.  Does anyone have any ideas?  This is weird!

I've attached some images (sorry they're very, very blurry) to hopefully shed some light.

EDIT: The contrast wheel does, in fact, still affect the image, but there are no visible graphics like the black startup bar.