For many of the capacitor failures in an A1200 or A600, the first you will see of the failure is when the cap has already eaten through the track on the PCB and damaged it. By the time you see the failure and your Amiga doesn't boot any more, the damage is done.
If the failed cap happens to be on the audio output, you will get advance warning of the failure as the sound will go quiet. Anywhere else and you won't.
When it comes to electronics where the system has a known weakness, such as the caps in the A1200, prevention is better than cure.
Or you can wait until the cap has eaten your track, your machine doesn't boot, and then buy another board.... but what happens when all the boards are gone?
Why do I think this? Because of the number of A600s and A1200s I have fixed which have failed because of leaking capacitors eating PCB tracks - all of which could have been prevented had their owners had their machines recapped before they leaked.
