HPS1 and HPS2 interlocks on a 407 Controller.
According to the manual the HPS1 interlock is typically caused by low fluid level and the HPS2 is caused by a fluid over-temperature condition (Figure 1).
Figure 1 – Page 313 of the 407 Manual PN 011-949-900 H
If you have neither of these conditions then there could be a problem with the cable between the controller and HPS or in the 493.07 converter box if you use one.
There is an HPS jumper plug part number 495384-01 (D-15) or 39799-01 (CPC) that can be used to jumper the HPS connector on the 407.02 processor module on the back of the controller (Figure 2). If you can clear the HPS1 and HPU2 interlocks with the jumper that indicates there is not a problem with the 407.02 processor module.
Figure 2 – Location of HPS jumper plug on back of 407 Controller
If putting a jumper plug on the HPS connector on the HPS itself allows you to start the HPS locally then the problem is somewhere between the HPS and the controller. If you have a 493.07 converter box check the fuses inside and make sure the HPS cables are connected from the controller to the converter box and from the converter box to the HPS.
If you don’t have a converter box you need to identify the part number off the Wye-Cable between the 407’s HPS and Remote E-stop connectors and the HPS connector. The part or material number is printed on a white label near one of the cable ends. With that the cable pinout can be identified to check the cable for continuity and shorts across wires.