I've rechecked those connections several times after reading about somebody having trouble with q3. It is blurry right there in the photo I'll admit but looking through the magnifying glass, those joints look just as good as all the rest. I reheated them again just to make sure.http://youtu.be/qE80_rIxrlw
This is another video. This time I made sure all the capacitors were below .01v before powering on the clock. Almost all the digits come on initially. You can skip near the end of the video and you can see eventually the majority quit working. When I ground out the bias pin, you can see all the digits actually do work. Eventually, given about 5 minutes, all I get is an occasional single line on the second to last digit blinking.
I got some better photos of the top of the board. If you are correct in that grounding out the bias pin should shut the display off, it makes me wounder, did I put something in backwards? I can't see under the components to check the positive negative obviously, and I can't find a diagram of the silkscreen so I'm not sure how to check. But here are those photos.
I've got 2.02 volts on the bias pin.