How do we know when to change the other caps?

What symptoms would we get if the other four caps are bad? They don't seem to get as much voltage as what is near the power supply. On the Soyo board we also only replaced caps near the power connector and we are told it works fine now though was flakey before. And that the caps near power connector are filters to keep the voltage constant. Can you check for bad ones without removing first?

1999 Board had 10 1000 microfarad 10v 105 degree NRSY capacitors, some bulging, and was dead on arrival. Replacing the four near the power connector and two other suspicious ones revived it. The other capacitors on the board by a different maker are okay. Came with Slot1 600MHz cpu. /////// Another Supermicro board is fine - P6SNE 1996 with two Socket 8 slots and Pentium Pro Overdrive 200MHz cpu. /////
We learned of this problem from a friend whose Soyo board we recapped. Thanks for a wonderful site. This is now our fastest board.