72 Dart Dash Circuit board

We assume the board is the fault? A bit of info that may help.
Circuit board contact pins and copper traces support only the positive side of circuits. Fault can be the ground side. Screws that attach the board to the housing are part of the ground path. So screws/washers need to be snug to the copper pad on the board beneath them. Stripped screw threads can be the fault.
The lamp sockets have tiny plastic tangs holding them against the board. Distorted or broken tang will cause lamp inop.