Unfortunately, Nintendo cheaped out when it came to the VB. The ribbon cables that connect the motherboard to the display LED board isn't soldered; they're GLUED. So even with old new stock VBs, the glue will degrade and relax the pressure, losing connectivity.
It is possible, though not for the faint of heart, to open the VB, remove the glue, scrape away a bit of the ribbon cable to reveal the metal traces, and solder those traces to the LED board. This is a permanent fix, too - unless you screwed something up, you'll never have to worry about the display glitching again...well, for connectivity issues.