If you cannot find the PDF, do not worry. The motherboard silk-screens (the white text printed directly on the PCB) are your manual. Look closely at the board itself:
The 3-pin or 4-pin chassis fan header defaults to "Full Speed" in the BIOS. Solution: Enter BIOS -> Hardware Monitor -> Set "Chassis Fan" to "Auto" or "PWM Mode." If the option is grayed out, use a low-noise fan adapter cable (hardware solution). acer h81h3am v10 manual
Acer does not sell this board separately, so there is no standalone motherboard manual. Instead, the documentation is included in the full service guide for the specific desktop model. If you cannot find the PDF, do not worry
Best sources for the service guide (contains board layout, jumper settings, BIOS info): The 3-pin or 4-pin chassis fan header defaults
ManualsLib / ManualsPlus – Search for “Acer Predator G3-605 service manual” or “Acer Aspire T3-715 service guide”. The motherboard section will cover the H81H3-AM.
ElektroTanya – Search for Acer H81H3-AM. Service manuals are often available in PDF.
