"Beep" when testing VCC and GND with the multimeter
Sounds like capacitors to me. Since the multimeter is most likely verifying continuity with a DC supply, an uncharged capacitor will appear like a short for a brief moment.

Also found this at https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter/continuity:


  Continuity and large capacitors: During normal troubleshooting. you
  will be probing for continuity between ground and the VCC rail. This
  is a good sanity check before powering up a prototype to make sure
  there is not a short on the power system. But don’t be surprised if
  you hear a short ‘beep!’ when probing. This is because there is often
  significant amounts of capacitance on the power system. The multimeter
  is looking for very low resistance to see if two points are connected.
  Capacitors will act like a short for a split second until they fill up
  with energy, and then act like an open connection. Therefore, you will
  hear a short beep and then nothing. That’s OK, it’s just the caps
  charging up.