There is a pretty massive IC there with a clock so I would say
it needs the board. More than remote going on I would say....
Try e-bay for a part out. May take some time but a better chance
than most. Also watch for free sets on Craigs list. A parts set
is a nice thing to have.......
BTW never mess with the light box/engine on any of these type sets.
You will soon be holding a knife to your throat ! Even the best techs
in the Boston area only changed things at board level & still had troubles.
best luck
73 Zeno
LFOD !