ACER AN517-42-r85s not booting

jon766

im a rusty but previously very seasoned IT pro, now working in CyberSec.

I have a Acer AN517-42-r85s from 2012 which has been working fine untill now.

Took a windows 11 update last week and computer no longer boots beyond a black screen with red key board. no acer log, no BIOS access.

troubleshooting

held power button down untill computer powered off.

diconnected power, disconected battery, disconnected CMOS battery, both bateries for 30 mins.

removed and reseated RAM in diffrent slots, tried exsternal display, tried FN+ F2,F5, F6.

atempted BIOS recover using FN+ESC, boots to "high speed fan mode", no USB activity.

open to other suggestions but I am thinking its a BIOS issue, can someone provide a proven BIOS recovery process for a system that "cannot past POST"?

ive tried geting BIOS files and renaming it to "RCVBOOT.CAP" and using all 3 USB ports on the system. as stated no USB activitiy.

any assistance is apprecated.

Thank you!