Re-capping A 15 Year Old Solid State Amp

1. 15 years isn't old if it had been always used and i'd probably give it another 5...10 years safe.
2. Amp in need of recap may increase noise level when in idle or even start humming for no reason.
3. You may do visual inspection on how clean the caps look and how clean the PC board where they're connected and if you spot traces of heat or liquid, it's another sign.

Ebm,
Let me know when you have your old amp on curbside.

Ebm - In your statement "I won't buy a 15 year old amp as its history!!" all I can say is you must be buying throw-away junk!!. I have owned many Solid State and Tube amps much older than that from reputable companies (ARC, Conrad-Johnson, McCormack, Bryston, etc.) who use high grade components and there is no problem.

Sorry jump on a 15 year old amp ASAP!!!!!!

I am not implying that one should purposely buy an amp 15 years old or older, but I am saying that I don't think they should be afraid to either, if it is made of quality components. There is no reason to be afraid of an amp that was not manufactured on or after the year 2000 because it is now 15 years old. That is all I am saying and I apologize if it was misinterpreted.