SK40 and Voltage regulator

[alongpali]

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?

[zhenning]

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?

Hi,

Did you read the datasheet of LM317?

The LM317 middle pin is adj that allows you to adjust your Vout. Are you sure you connect the pins correctly?

[alongpali]

My apologies.
I thought, the LM317 is similar with LM7805.
Thx for your concern~