Suddenly no keyboard, trackpoint, or touchpad M4500

Ubuuntu 14.04 been running great for a long time. While using it recently it suddenly was unresponsive to any inputs. No reboot fixes it. Doesn't work even to get into bios. I took the keyboard out and checked for corrosion on contacts, found none, reinstalled, still nothing. USB keyboard and bluetooth mouse work fine.

I would like to point a finger at Ubuntu...but it doesn't work pre-bios. I would like to point a finger at the keyboard, but the touchpad doesn't seem to be a part of the keyboard. I guess I point a finger at Dell?

Thoughts? Any diagnostics I can run instead of just throwing parts at it (I hate that method)?

 

If it doesn't work pre-BIOS, no diagnostics I can suggest (although you could try holding down Fn on boot, just in case that goes into diagnostics). You could also see if the screen self test works:
o run the LCD BIST (Built in Self-test):
Press and hold the D key on the keyboard while pressing the Power button, then release both at the same time.

Failing that, opening the bottom and re-seating the keyboard and touchpad connectors is probably the quickest and easiest thing to try.

You might see if the CMOS is resettable on the M4500 by pulling a battery. If so, can't hurt to try.

Unfortunately, given the low odds of the keyboard and touchpad going out at the same time, the odds are annoyingly high that it's the motherboard.

 

Open the computer and the keyboard and mouse suddenly work for 3-4 months and now they've quit again. Going to replace the motherboard.