It has come to our attention, that recent updates to macOS Monterey can brick some older Macs. Please read the article below, we hope it helps.
macOS Monterey Failed Installation
The issue can be resolved but does require hardware attention from a technician or a complete wipe of your system resulting in all data being lost. Please avoid updating for now.
The issue primarily affects older Intel-based Macs and can cause the system to brick, becoming unusable until fixed.
Follow the link for more information. Apple has made a statement saying they're working on a fix.