Laptop won't turn on after Keyboard replacement

Hey Dell Community.

I've got a DELL XPS L521x that has been bullet proof for many years now (it got my wife through Nursing school)

Some of the keys started to stick so I ordered a replacement keyboard and swapped it out and now it won't turn on. I've tried many of the standard fixes:

 - doing a power drain
 - trying only on A/C power
 - trying with a different A/C adapter

But this seems to be a strange issue. I'm an IT guy by profession but i mainly work with servers and Virtual machines.

The Keyboard backlight turns on immediately when I press the poser button, but the power button does not illuminate (like it used to). I can hear some noises but they're not the familiar boot noises i've heard from the computer for years, it's like it's hung/waiting for something.

I tried the Power + D boot to do the LED test, but nothing happens.

Please help me resurrect the laptop that my wife and i both loved.

Thanks!

 - Tim