A bad display will do that. You can unplug the displays and plug them in one at a time (machine off when plugging and unplugging) and put you finger on the resistor (but watch out they get hot quick) and figure out which display has the issue. You can switch the bad display to like player 4 or something and leave it unplugged till you get a good replacement. If you have a couple bad displays it may be better and cheaper in the long run to get a whole new set of displays and master. Some people have had trouble with rottendog products but their display sets are great and I have never heard a single bad thing.

By the time you have to buy 2 replacement displays the cost is close to a whole new aftermarket set The colors match great and don't need the 100 volt from the power supply.

If the current limiting resistors are burning up i'd imagine the HV driver chip or a display has a problem.

Reducing the voltage won't help the resistors burning up. They'll keep burning up until you fix the issue. Travish and barakandl have given you good advice. You either have a shorted display or a bad HV driver chip. In my experience it is usually a shorted display glass.