A hair dryer and a can of freeze spray can be very helpful lacking an ESR meter. If you can't find freeze spray, hold a can of air duster upside down and you will get pretty much the same thing, just be careful not to let much of the liquid drip on your skin or you can get frostbite.

Heat up areas of the board with the hair dryer, don't go nuts, just get it a bit toasty and fire it up. If it works, hit the caps one at a time with freeze spray until something happens. Any noticeable change in performance means it's a bad cap. Works sometimes on semiconductors too, I finally used this technique to locate a faulty FET that was causing intermittent scratchy noises in an old stereo receiver.