SPI dump attached, Service tag: 382M893, board LA-J143P
the 3 orange LED blinks happening. Initially the computer'st BIOS self detected corruption of itself and attempted to recover. However it was failing at the very end mentioning it can't downgrade. I indeed disabled downgrade possibility in past but don't understand the reason was this should prevent flashing with same version. Neither full self-revovery or providing it on USB worked and after some attempts it corrupted completely.
The verified dump attached, BIOS section is completely broken, - at its offset it seems to be overwriten...