take the cover off the flyback, turn off all the lights and see if any sparks are comming from the fly... if nothing.. keep everything on for 15-20mins.. turn the game off... then very lightly touch diffrent parts on the chassis on the monitor (looking for sopts that are very hot)
if you feel something very hot then chances are that component is causing the trouble.
but yah also check to make shure everything is pluged in tight, long rides can sometime's losen up connections... also make shure that all your plugs where the wires goes into the plug/clip that they are pushed in all the way.
i hope this can help you, pictures would be nice to see, of the probem on the monitor and of the chassis,
also another thing you can try is switching out the game pcb for a diffrent one to see if u get the same problem, if you do have the same problem you know its not the pcb and its somthing on the monitor thats causing your problem
also another thing to check is on the neck on the monitor thair is the color switchers (i know thats not the correct term) this is on the neck not the pcb board connected the to end of the neck, look to see if they have some type of glue on them so they do not turn, if these do not have some type of glue then maby while on its jurney they mite of turned some and thats what causing your problem