Kb926qf Datasheet [updated] Page

; Select logical device (e.g., UART A = device 0x02) MOV AL, 0x07 OUT DX, AL INC DX MOV AL, 0x02 OUT DX, AL DEC DX

Ensure the chip is getting its 3.3V standby power. If this is missing, the issue lies in the 3.3V standby power IC, not the EC. kb926qf datasheet