OR, you can do it RIGHT in the first place. No need to check then. If you can't see a short, and all your wires are going to the right place, then there is no reason to check. Also, hail, if you put the meter in your line of vision of the probes like I do when I'm checking gamecube voltages, then IMO it's much better than a beep. It's preference, there is no arguable reason why one is better overall than the other.
If you turned on your n64 and it's sleeping/dead/whatever, congrats! You fail!
Look, I've learned one truth about n64's in my 4 years of portablizing. It's that you can never let the n64 know it's not in its original case, and you can never let it fall asleep. If either of those happen once, then your n64 will have random problems later.
Go into a cart slot relocation slowly and take your time. Even in my speed run I tinned the n64's pins first and then soldered. It's that important.
SS