In 1980s, aluminum electrolytic capacitors with quaternary salt were used. It was said high performance and long life. Many companies made them. But about 5 years goes, they started leaking solutions that was high pH (having strong alkalinity). It was found that quaternary salt became alkaline belong long time use. That problems was not found in condensed test in labs. As a result, almost high performance caps in 1980 leaks in about 10 years. High pH caps not only leaks but makes short circuit. Then one day, PSU fires.

To prevent break down,we must need to renew all caps. But now, it is too late. Almost PSU is broken,isn't it?

We must replace not only caps but zener-diodes, photo couplers, some transistors, resistors, and so on. Ideally, all pars to be replaced but some parts was discontinued.

I researched succeeding parts, but it is imperfect. Any advices is welcome.

p.s. Original X68000 PSU seems not to use quaternary salt. But they are too old, so they should be replaced.