Nope, it didn't work in Linux and the version of bios in this outimage is already the latest one....

Manufacturing mode and no service tag. Still no sound detected in manufacturing mode or after entering Service Tag and alt+f....

It was done by bios.exe updater from dell support page. After that I tried to downgrade or update in the same way but results were the same no sound and the message .
Also I noticed that message and ME descriptor thing appear depending on which dump was initially flashed in chip and persist after downgrade/update of this initial dump via dell update exe to every version of bios....

Dell Precision 7540
S/T: GLCXK33
EDA50 LS-H271P
Rev: 1.0 (A00)

Hello. No realtek sound in OS.
After bios downgrade to version 1.8.3 laptop has such problems:
1. Shows message "Alert! Service mode jumper is set" during every boot. And ME Flash Descriptor is unlocked in OS.
2. Realtek chip and its devices are not detected in Windows(device manager) and Ubuntu. But speakers work(beep) in built-in diagnostics. Those speakers' pins are connected directly to codec so it seems to be alright.

So far I:
1. Flashed different ME...