Lifespan of a quality solid state amplifier?

Herman I repair 5v 200 amp switching power supplies and find that 70-80% of the fails are in the large filter caps used in the supply section;when I replace these caps I change all electrolytic caps in the supply as well as the fan.The supplies I see range from the 1990's and run 24/7 being used in large semiconductor test equipment;they are normally mallory 15000mfd at 7.5v and 4000mfd at 200v caps.
Did you company resolve their computer failures?

I am in the same boat with Ralph as the mallory caps I see in 5v200amp switching power supplies also have the greyish white vent plug positioned half way between the plus and negative terminals on the cap;they will start to push up and show signs of leakage.Once the electrolytic gets on a pcb it damages the board and shorts seem to start occuring thus rendering the mainboard unrepairable.

Rower30 if you were to do a DPA (destructive parts analysis) you would definetly see what 30 years of use can do to a capacitor and it will have a audiable affect when being used in audio equipment
What Herman says is spot on in and is what I see at my military customer sites who do this procedure using sems (scanning electron microscopes) and highly accurate test equipment.