I have completed installing the replacement motherboard. The 8930 is starting and restarting successfully and without the two error messages, (A7) ME FW Downgrade – Request MESpiLock failed and Error sending end of POST message to ME:HECI disabled, proceeding with boot. The motherboard was the causing my issue. The board was not difficult to install as I have built one desktop. Thanks for your time and guidance as we got this 8930 running again. Not sure how but if I can help but I will read posts and provide responses when I can.
My Dell XPS 8930 (warranty expired in March 2020) will not boot from a start or a restart. A diagnostic code of 2 + 1 amber lights from the power button appears. This error code means a motherboard failure for a 2018 manufacture year. If a forced shutdown using the power button is done, the AC cord is disconnected for 15 seconds then reconnected, and the power button is pressed the 8930 will boot with two error messages. The two messages are “(A7) ME FW Downgrade – Request MESpiLock failed” and “Error sending end of POST message to ME:HECI disabled, proceeding with boot”. These two error messages will not appear if BIOS Setup is accessed then exited. No changes need to be done. Just the act of accessing and exiting BIOS Setup will result in no error messages. But only after the BIOS exit instructed restart fails and another unplugging of the 8930 AC cord. Any subsequent attempt to boot will fail every time with 2 + 1 amber lights from the power button. This summary is detailed below and are my efforts for the last three weeks to fix my desktop. Sorry for the lengthy request. I have researched this forum and many others, learned some things about boot, POST, BIOS, ME and Dell Support insufficiencies,  and still cannot find a way to repair these boot failures. My 8930 is out of warranty. Any help will be appreciated.  Start and Restart BIOS POST  The PC must be subjected to a hard shutdown using the power button and an unplugging of the AC cord for 15 seconds for the POST to complete. The Dell logo screen appears with a bar at the bottom, and that bar fills up completely and disappears. The POST will not complete if the PC is cold booted or warm booted without the unplugging of the AC cord.  Hard Reset  Performed a hard reset or clearing the CMOS. Removed the battery for 23 hours. Restart failed. Performed a hard shutdown and unplugged AC cord for 15 seconds. The PC started to the sign in screen without error messages and sign in was successful. Attempted a second hard shutdown and unplugged AC cord for 15 seconds. Error messages returned. CMOS battery tested 3.174 VDC. Hardware Inspected motherboard for swollen or burst capacitors. None found. Power Options Turned off “turn on fast start”. Restart (warm boot) and Start (cold boot) failed. Resulted in 2 + 1 amber lights on power button. Chipset Driver Chip Set Driver: performed driver update scan from Dell Support webpage, no updates found, opened device manager, selected Intel® 300 Series (Z370) – A2C9, selected Properties, selected Driver tab, selected Uninstall Device, then reinstalled chipset driver, no change in restart and start issues, original chipset driver was oem84, Dell Support installed oem39, used system restore to revert to the original .inf file TMP No change in restart (warm boot) fails and start (cold boot) fails, TMP is not causing failed start, failed restart or error messages. Test Results Not performed Dell 8930 specs: WIN10 Home Edition 64 bit, version 21H1 CPU: Intel I5-8400 GPU: NVIDIA GeoForce GTX 1050Ti, 4 GB GDDR5 RAM: 16 GB at 2666MHz dual channel System Disk: 256 PCIe x4 SSD Data Drive: 1 TB 7200 RPM HDD DVD/CD Drive Bay WAVE MAXXAudio Pro Wireless Module: 802.11ac 1x1 WiFi and Bluetooth 4.1 Dell wireless mouse BIOS version 1.1.17 BIOS Mode: UEFI Motherboard: 0DF42J version A00
XPS 8930, MESpiLock, HECI Disabled error messages