Hello, thanks for reaching out to us.

Could you please run the hardware diagnostics once by tapping F12 during start and run the test. Let me know if its passed or failed?

Also, the operating system you are using was it originally shipped with the system?

Go to Control Panel\All Control Panel Items\Power Options\System Settings and check what is selected under "When I press the power button" change it to "Shut Down"

I am running Ubuntu 18.04

The thorough Diagnostic Tests passed successfully, although it could not detect the hard drives.  I got

"Msg:  Hard Drive - No Hard Drive Detected, or disk controller not supported"

but the controller / hard drives are seen in BIOS, on startup, and in the the OS.

The issue happened again when I exited the BIOS, fans to max, screen black, no reboot.  Had to disconnect/reconnect power to get the system back.

BIOS:  A17 (latest)    /  Additional Sleep states :  Disabled (unchecked)

OS:  Ubuntu 18.04

Power setting in OS:  Automatic Suspend: Off    |   when the button is pressed : Power Off

Has the size 2032 CMOS battery been replaced in any recent history?  If not, 7 yrs. is quite a stretch for battery that lasts around 5 yrs.  A low battery can cause all sorts of bizarre problems.

If replacing it doesn't work, at worst you'll have a new battery.

I'd get either Energizer or Duracell lithium.  Sony only lasted me 2 yrs.

Precision T7600 Owner's Manual 

Battery has been changed to a nice shiny Duracell.  I left the battery out for a minute and pressed and held the power button with the power disconnected.   I got the invalid config message on boot and when into the bios and changed the settings.

No change in behavior.   as soon as i exited the BIOS, fans to max, and no boot screen.

disconnected and reconnected the power to get the system to boot.

Hello, 

Thanks for the detailed description. As per the message in the diagnostics did you receive any error and validation code or just HDD not installed?