You have another board i have a 820-0174-c but i see a scratch between the ROMs and the connector and because the board is green and not really flat i cant tell if the scratch has broken the trace.
If it was not as tight i would use pencil lead to try to give the trace more conductivity but that would just make it worse.
I only do that for corrosion on old games. Would the ROMs cause the blank grey screen and no boot sound?
Pencil lead is conductive, but will have much more resistance than copper, according to a quick Google search. If you have a broken trace it would be best to do a patch wire from the source to the target of that trace.