SK40 and Voltage regulator

I am using 12V supply towards sk40.
using a multimeter, Vdd output for sk40 is approximately 5V.
I need to step down 5V to 3V as output.
So that, I am using voltage regulator (LM317).
The PROBLEM is, when I try to switch on the voltage regulator, Vdd output drop from 5V to 1.6V.
1.6V reading I gain from A point. No voltage at B point.
This is the diagram for my voltage regulator.
It is about the capacitor?
using a multimeter, Vdd output for sk40 is approximately 5V.
I need to step down 5V to 3V as output.
So that, I am using voltage regulator (LM317).
The PROBLEM is, when I try to switch on the voltage regulator, Vdd output drop from 5V to 1.6V.
1.6V reading I gain from A point. No voltage at B point.
This is the diagram for my voltage regulator.
It is about the capacitor?