Help regarding voltage regulators.

Hi! I'm currently having problems with my voltage regulator circuit. My input voltage is 42V. My first voltage regulator steps down input 42V into about to 12V, I then paralleled a L7805CV that uses the 12V as its input to have an output of 5 volts. I used the output of the L7805CV as an input to a LM317 voltage regulator. The problem is that when I measure the output at the LM317, I only get about 0.5-0.54V when I configured it to have an output voltage of 3.3v. can anyone please help me? Thanks.

Have you got it wired correctly? Note that the LM317 has a different pinout to the 7805 & 7812.

LM317 needs about 3v across it. Try jacking up the output of the L7805CV. Or make the input of the LM317 12v.