have you tried any ACPI boot flags? try disabling it...

acpi=off Don't enable ACPI

acpi=ht Use ACPI boot table parsing, but don't enable ACPI interpreter

acpi=force = Force ACPI on (currently not needed)

acpi=strict = Disable out of spec ACPI workarounds.

acpi_sci={edge,level,high,low} Set up ACPI SCI interrupt. EX: acpi_sci=edge

acpi=noirq Don't route interrupts


Also, try obtaining an ACPI kext and putting it in your Extensions folder.

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