HP Z2 Mini G3 Workstation No Power

[360Outlok]

Purchased (auctioned) a used HP Z2 Mini G3 Workstation Entry.  Did not come with a hard drive or power brick.  Added SSD and restored to Window 10 Pro.   Everything worked fine.  Did several Windows update requiring restarts.  Everything worked fine.  Shut down over night.   Attempted to add additional memory.  Open the case and flipped up the heat fan to replaced the RAM. Installed the memory and plug the power back.  Red light indication near the plug came on.  The red light is solid.  Closed the case and press the power switch in the front.  Nothing happened.  Did a long press and released.  Checked all the connections from the wire to the motherboard.  Nothing looked loose or broken.  I replaced the small battery inside.  Nothing happen when I pressed the power button.    I order a new power switched and waiting for it.  Does anyone have any similar situations and found out what the problem was.

[erico]

Did you install two identical memory modules that are guaranteed compatible or did you add a module to the empty slot?

Unplug the power  and remove the memory modules. 
Put the workstation back in the original configuration.

After flipping the cooling fan to its position, plug in the power cord and press the power button.

If the workstation boots up you have just proved that the problem is with the memory module(s) that you installed.