The computer worked fine until I removed the not working DVD drive to get a part number to order a replacement. I left the bad DVD drive out of the computer. A day later I turned the computer on and it did not continue past the POST. Pressing F2 gets me into the BIOS config with no problem. I disabled Quiet Boot Mode and saw more POST information. No error messages appeared in the DMI. The hard drive appears in the BIOS information screen. I turned the computer off and installed the DVD drive. When restarted the DVD drive and hard drive appear in the BIOS screen. I changed the boot order. Same problem. I removed each memory 1 at a time DMI did show the decreases in memory. I removed, hard drive, and set the BIOS to boot first from USB storage stick. Same problem. I removed all boot devices. Same problem. During POST a line says "NO TPM or TPM has problem" . No missing drive or loader messages appear. The screen remains back lit but no display. The keyboard also locks up. I removed the CMOS battery. When replaced, I reset the time and date. Same problem.