What is the lifespan of a good SS Amp


Consider to go for a used SS Amp.
Around 4-5 years old.
Wonder how long one good SS Amp lasts.
I know that some 20 yo tube amps cost more than their
original retail price and they may last for centuries
(just need tube change)
but wonder how it is with the SS.
If I go for 4-5 yo SS Amp will I be able to enjoy it for a long years or after another few years it will start giving me problems.

Thanks for your help.

kdbg00
This is an interesting read. I have a White Labs a100. It has a problem not mentioned,so far. A transformer on one ch. has quit. So far the price has been to high to replace, because both transformers 'should' be replaced. I'm just guessing,I figure this to be of mid 90's vintage??(Which are far from 20 years of service)
I bought a Sansui AU6500 integrated amp, new, in Sept. 1974. Over 30 years later, it is still going strong, only problem with it is the little orange LED to indicate it was on burned out about 25 years ago. As a matter of fact, the amp is doing duty at a Cold Stone Creamery ice cream store about 11 hours a day 7 days a week providing music.
I own a Jeff Rowland 302 amp."It's a proprietry digital switching power circuitry amp and not a class D amp", in the words of one Stereo Times reviewer. Jeff calls the circuirty MECC (Mutivariable Enhanced Cascade Control). This amp hardly even gets warm. I was wondering what kind of longevity this type of amp would have?
They could last close to a lifetime. I am still using my Marantz 2285 solid state amp in the basement from 1978! Other than some bulbs being replaced and a good internal dusting and cleaning its still going strong!