Did not see any evidence of any capacitor leakage when I had the chassis out. And there is no audible signs of this either. FWIW, I just sent my 1978 Mark I in for a reverb addition and general inspection last year. The ORIGINAL caps were replaced, but only for precaution. I had no evidence of capacitor failure in this nearly 30 year old Boogie. I told Mike to replace anything it might need in the next 10 years.