[TV MAN]

I'm into a mid 1990's tube guitar amp that failed a 6CA7 output by developing a carbon path between the plate pin and heater pin. Tube tested short, and found the burn marks on the tube socket and later tube when I went to replace. So, tube sockets on the way and a pair of Mullard outputs in hand. Now, my question - this uses "modern" electrolytics in the power supply. They are more than 20 years old. No signs of overheating. Should those be replaced as a preventive or left as long as things look and work ok? I dont want a repeat.