Why Samsung J5 won't power up with power supply?

Hi, I was a cell phone repair and after several years spending out of this career I came back to the business again.

I have a Dazheng PS-305D DC power supply which works almost fine, but it can’t power on some new phones mostly Samsung phones.

I put the power supply current to maximum and the voltage on 4.0

When I press Power button,the phone starts and after showing logo of what manufacturer it is, it boots again and again. it never comes up.

It should be noted that this happens to 70 percent of phones.

So, what do you think? Is it a problem with my power supply? Am I doing anything wrong?