Jolida JD-9 Upgrade

I've had my Jolida JD-9 phono stage for over 20 years, and it's been even longer since it had its Level 3 upgrade done by PCX.  Is there a time when it needs the opamps, caps, etc., replaced short of failure?  Nothing lasts forever, and I haven't noticed any change in performance.  If it needs it again I'm going the DIY route.

Thanks,

John Cotner

New Ulm, MN